I've struggled with the same issue for months (Office 365, Win 11, wired desktop PC) and what I read seems to lean towards mostly network issues after wake from sleep.
This morning I tried running a couple of commands from the CMD prompt (i.e. Start -> cmd).
ipconfig /release
ipconfig /renew
Basically these disconnect/reconnect your network connection.
My Outlook was already open and unable to get new mail before doing these commands, but once completed new mail came to inbox.
I agree we as customers of Microsoft Office should not have to deal with this type of issue, but for now I'm going to write a batch script to do these commands for me until it gets resolved.
Hope someone finds this useful.