This list is a good summary. We have a lot of issues with logging in and two factor. Initial login and setup is particularly fraught.
And Teams. Everything.
My personal favourite is document format screw ups (‘corruption’ might be the right word) depending on which Word was used (app, browser, Teams Word). It’s such a shit product. Document footer problems and page numbering issues are a complete waste of my time.
Spending the first 10 minutes of every call trying to get sound working for everyone. Hey Teams, don’t switch what mic you are using.
"I can't save outside of onedrive"
"My mails aren't getting delivered"
"My office suite has deactivated itself and won't reactivate"
"We need a shared mailbox for x,y,z"
"The new joiner can't access my onedrive/shared drive" (No groups/auto-groups - they require some more advanced administration or discipline).
"I received an email from someone impersonating the CEO asking for an invoice to be paid immediately"
"My Excel sheet is somehow not syncing to onedrive and now there's conflicts"
FD: We don't use Teams, and we migrated from o365 to GSuite, but there are some people who remain on o365 for Office reasons.