Wi-Fi is unstable after macOS Tahoe update on MacBook Air

Ok everyone, after a couple hours on the phone with Apple Support, the issue is.....FIXED(???)!?

After several steps involving "sudo diskutil resetUserPermissions / `id -u` " from terminal, "repairHomePermissions" from Recovery boot terminal, reinstalling Tahoe, rerunning resetUserPermissions because my entire user folder was inaccessible after reinstall (would not recommend), booting in safe mode, creating a new network location, uninstalling Windscribe, all of which did nothing...

We went System Settings > General > AirDrop & Handoff, and switched Handoff off, AirDrop to No One, and AirPlay Receiver off, my network connection completely stabilized. Even after switching all of those back on, my network has SO FAR remained completely stable.

I'm testing my network by running a continuous terminal ping to my router IP, which previously was showing an average around 3ms and then a spike every few seconds up around 50-100ms; now it is hovering steady around 3ms. My remote gaming Shadow PC which was previously getting choppy video/audio is now working smoothly.

So at this point it's unknown exactly which feature was the problem between Handoff/AirDrop/AirPlay, but it seems like something in one of those configurations that got corrupted in the update was reset/recreated by switching them off and on. I'd recommend everyone give that a shot and write back if it works for you, I hope so! And I'll let you know if the problem comes back.

You could also try these

Forget your Network and delete the Wi-Fi configuration files

Go to System Settings > Network > Wi-Fi, click the three-dots button next to your network, and select Forget This Network.

From the previous tip in the thread

To reset network preferences on a Mac by deleting .plist files, disable Wi-Fi, open Finder, press Command+Shift+G, enter /Library/Preferences/SystemConfiguration/, and delete files like com.apple.airport.preferences.plist, NetworkInterfaces.plist, and preferences.plist to the Trash. After restarting the Mac, your system will regenerate these files with default settings. 

Steps to Reset Network Preferences

1. Turn off Wi-Fi: Click the Wi-Fi icon in the menu bar and select Turn Wi-Fi Off. 
2. Open Finder: Click the Finder icon in your Dock. 
3. Use "Go to Folder": Press Command+Shift+G to open the "Go to Folder" dialog box. 
4. Enter the Path: Type or paste /Library/Preferences/SystemConfiguration/ into the box and press Go. 
5. Delete .plist Files: Locate the following files in the SystemConfiguration folder and drag them to the Trash: 

• • com.apple.airport.preferences.plist
  • com.apple.network.identification.plist (if present)
  • com.apple.wifi.message-tracer.plist (if present)
  • NetworkInterfaces.plist
  • preferences.plist

1. Empty the Trash: Right-click on the Trash icon in the Dock and select Empty Trash. 
2. Restart Your Mac: Go to the Apple menu and select Restart. 
3. Re-enable Wi-Fi: After your Mac restarts, turn your Wi-Fi back on from the menu bar. Your Mac will automatically create new default .plist files, and you'll be able to reconnect to your network. 

Reset your Location Services 

1. Go to System Settings > Privacy & Security > Location Services.
2. Turn off Location Services.
3. Next, restart your device from the main Apple menu.
4. When your Mac relaunches, turn your Location Services back on.

Use Terminal to reset your DNS and network stack

1. Open Terminal from Finder > Applications > Utilities.
2. Run this command: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
3. Enter your admin password and press Return.

You can try this. No guarantees it will work.

To reset network preferences on a Mac by deleting .plist files, disable Wi-Fi, open Finder, press Command+Shift+G, enter /Library/Preferences/SystemConfiguration/, and delete files like com.apple.airport.preferences.plist, NetworkInterfaces.plist, and preferences.plist to the Trash. After restarting the Mac, your system will regenerate these files with default settings. 

Steps to Reset Network Preferences

1. Turn off Wi-Fi: Click the Wi-Fi icon in the menu bar and select Turn Wi-Fi Off. 
2. Open Finder: Click the Finder icon in your Dock. 
3. Use "Go to Folder": Press Command+Shift+G to open the "Go to Folder" dialog box. 
4. Enter the Path: Type or paste /Library/Preferences/SystemConfiguration/ into the box and press Go. 
5. Delete .plist Files: Locate the following files in the SystemConfiguration folder and drag them to the Trash: 

• • com.apple.airport.preferences.plist
  • com.apple.network.identification.plist (if present)
  • com.apple.wifi.message-tracer.plist (if present)
  • NetworkInterfaces.plist
  • preferences.plist

1. Empty the Trash: Right-click on the Trash icon in the Dock and select Empty Trash. 
2. Restart Your Mac: Go to the Apple menu and select Restart. 
3. Re-enable Wi-Fi: After your Mac restarts, turn your Wi-Fi back on from the menu bar. Your Mac will automatically create new default .plist files, and you'll be able to reconnect to your network. 

This is really nuts that the manual IP seems to be the fix. After replacing routers, modems, trying every Wifi frequency, channel, clearing out all wifi preferences, moving my router around the house, this SEEMS to be the only thing that's fixed it, that is, assuming it holds. For it to work I had to use "DHCP with manual address" and also assign the IP from my TPLink router DHCP Reservation settings. Only doing it on the Mac side had no effect, while using the full "Manually" setting resulted in no internet access.

After following a strange recommendation in this thread, I created a new test Mac user account, and after a few hours of testing, performance seems to be...perfect??

Can some others test this so we can see if it's a viable solution?

If so.....

1. what the he¬¬
2. maybe something in the user account gets screwed up in the update? maybe it can be found/fixed/cleared?
3. can a user account be duplicated? or is there some other easy way to completely migrate everything from one account to another on the same computer? i doubt it...probably would need to be backed up, wiped, brought back w/ Migration Assistant, but would that bring the corruption with it?

I also actually tried testing using fast user switching, leaving my original/real account still logged in and "switching" to the test account, and it did NOT work, I had the problem on the test account as well. So apparently still having the original account open in the background was causing a problem.

Update: I reran tests on the 2.4GHz spectrum and the network is much, much more stable, even thought the speed isn't as fast as 5GHz. Of course by stable I meant stable in terms of Tx Rate (>= 40) and MCS index (Only once dropped to 3 and the rest is all >= 4)

--- 192.168.0.1 ping statistics ---
1000 packets transmitted, 979 packets received, 2% packet loss
round-trip min/avg/max/stddev = 1.778/92.278/2116.995/244.039 ms

2019 Intel mac here, running Tahoe.

Wi-fi to home router is broken after update but works on many other wireless networks. At home, I have resorted to manually assigning my IP address which solves the issue but indicates there's something wrong with the DHCP process. We have about 12 other devices running just fine on this 5Ghz Wifi network. This is the first time owning a Mac that I've had such an awful experience with a new update. Restarting router, deleting .plist files, removing networks, did not solve the issue—just a straight up manual setting of my IP. Wild.

This is intriguing, and baffling, at the same time. I'm going to give this a try as soon as I post this, but my assumption is the same as yours--"something" on our current user account is cause this. So, what happens if you take your new test user account and simply sign into your Apple Account (via System Settings)? Does the old behavior return in that case?

You probably see where I'm headed with this. If a vanilla/virgin user account does not exhibit the problem, but the same account immediately has the problem after nothing more than signing back into your Apple Account, then the problem is going to follow us even if we migrated to a new Mac user.

This is starting to remind me of an issue I chased years ago on my Mac where wireless would go wonky on a predictable cadence. Actually, this happened in two different cases for me. One case was ultimately due to awdl0 (ugggghhhh.... don't get me started on this one.) and the second was due to a Location Service running a background wifi scan. The channel scans hurt--anything causing our wireless radios to "pause" and switch channels is going to be noticeable at some point.

Anyway, talk is cheap. I'm going to try some things on this path you paved and see where it goes... thanks!

@alirezazgr and @ffjxc -- Maybe try the macOS 26.2 public RC? I upgraded to it last evening because of hoping it would help with some of the same wireless woes you've described here. I figured it couldn't make anything worse (although I know that is often not true).

I seem to be having a better wireless experience at this point on it. Maybe you'll have the same luck?

Ok, little bit more data:

• updated to 26.2
• repeated the whole network files/settings reset process such as this (and left Location Services disabled for testing)
• ran Disk Utility First Aid from recovery partition
• logged in w/ my Apple Account on my new test user

Behavior is exactly the same: bad on my current user, perfect on my test user.

I hear where you're coming from on the hardware problem angle. Hardware can, and does, fail at times.

But, I have been running the 26.2 betas for a bit and now the RC/GA. It didn't fix the wireless issues for me, though others' experiences could be different I suppose. I can tell you with confidence this issue presents itself across multiple Apple devices in my home, all of which are running version 26 of their respective OS flavor (iPads, iPhones, MacBooks). It would be a pretty wild assumption that half-dozen+ Apple devices in my house all developed a hardware issue at the same time.

I'm going to try @Shade of Blue's suggestion of trying a new user account. May not be part of any solution in the end, but it feels like something worth trying.

I also have this with my MacBook Air m4:

Wifi Symbol looks normal, but nothing is working anymore.

My workaround is disabling and enabling Wifi it to make it work again.

But yeah, this is a thing since Tahoe.

I have basically the same issue; it appeared on every single network I connect to, as long as I'm more than 5 meters away from the router; If I'm right next to my home router everything seems fine. I haven't found a working solution yet, and I don't want to risk anything destructive. I do see some interesting correlations: RSSI and Noise are all in normal range but MCS and Tx Rate are way lower than expected. It does help a little to be in a direct line with router but not much. I've also found this out of the console app: `Apple80211Scan:1502 @[1177.359131] ifname['en0'], total time [0.004092], err[-528350195], Apple80211Scan Failed`, anyone knows what this means?

PS. I've tried creating a new network config, forgetting the network, running Wireless Diagnostics (which just tells me to revise best practices for wifi). Pinging my router is unpredictable, sometimes resulting in ```100 packets transmitted, 98 packets received, 2% packet loss

round-trip min/avg/max/stddev = 2.359/4.743/12.269/2.030 ms```

and sometimes 70% packet loss and max 140ms latency. I'm kinda disappointed at how rushed Apple seems to be with Tahoe, first a bunch of minor issues, now this??? PPS. As I'm writing this my Wifi went out again and couldn't save this. my Mac also seem to have auto-forgotten my wifi password and just asked me to enter my wifi password (all correctly) 3 times...

MacOS 26.2 Tahoe, 2021 MBP running M1pro+16GRAM

Having the same issues. Out of the blue the wifi just stops working get the spinning colorful ball. I can't force quit apps, & have to do a force restart by holding my finger on the power button. Happens either at initial startup or a few hours into using my macbook air M2 but every single day. Just performed a force restart after using my mac for over an hour.

Think Apple must have brought over Microsoft Techs bc this never happened in the past. Roll out of new os' were seamless. Now they are always buggy. Apple needs to do better.

Spent 1.5 hrs w apple support & got nowhere. They couldn't even tell if it is a known issue to be addressed in the next update.

For anyone keeping track, the manual IP only worked for a little while, now it's back to the same old (running a 2020 M1 MBP on 26.1. Wifi performs well enough for most purposes but trying to use my Shadow remote gaming PC, the latency and packet loss is all over the place. Guess I'm stuck on ethernet for now, or using my old 2013 MBP that has no problem at all.