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

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.

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.

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.

I tried everything said here even set static IP for my devices but both my iPhone SE 2020 and my. Mackbook Air 2020 M1 are having problems with my home wifi...

Is there any other fix I can try?