MargeHomer wrote: Point #3: That's the whole issue, I can't see any of my Numbers or Pages documents on my iPhone.
I was asking about what you see at iCloud.com
Point #4: Yes, the account is the same (but just in case, how would I check).
At iCloud.com it has your account name, an email address, in the upper left corner. That's also true at the top at each device's System Settings>[name]>iCloud
I fear that you are seeing problems with this version of Sequoia. I can't really check, since I don't have anything running that OS, but I've heard that 15.8.1 has problems. You can try re-starting in Safe Mode. This bypasses certain potentially disruptive processes, and it often helps. Safe Mode is different for different computers, so see this:
Start up your Mac in safe mode - Apple Support
Mess around in Safe Mode, and see if the problems persist. Then go back to a normal start up.
Really, your best bet is to upgrade to Tahoe, certainly on your M1 Mac.