Pages, keynote and Numbers documents in shared icloud folder take too long to open

Pages, Keynote, and Numbers files in a shared icloud folder are taking 20 to 40 seconds to open. Preview, MS Word, MS PowerPoint, MS Excel documents in the same shared folder open instantly. If I turn off my wifi while it is opening, it will often solve the problem.

My internet is fast and I am not running a VPN, antivirus or cleaner program. This has been going on for a long time (multiple reboots for other reasons).

I tried apple support. They had me forget my wifi network and reconnect. This fixed the problem for files I had just opened before but not for files I hadn't touched in a while.

If this were just an issue of shared folder files taking longer, wouldn't it be the same for Preview and MS files? Any help would be appreciated.

System information:

• iMac M3 with 304 GB empty storage
• Sequoia 15.7.1
• Pages/Numbers/Keynote 14.4
• Wifi 200-300 MBps
• iCloud 1TB of unused storage