We have run into a issue with the following basic setup:
Windows 10 21h1 (pro/enterprise) - Autopilot intune MDM enrolled
Office 365 Apps for Business
Onedrive for business
The user recently said all his excel documents goes into read only mode and autosave button is not visible in the top left.
So what we saw was that that office produce was office professional proplus 2016. What it should be is office 365 apps for business
We deleted the HKCU office registry key and when he started excel, autosave is there. but once he restarted the app by openign another doucmnet (in onedrive of course), it dissapeared. same in Word too.
we clean uninstalled, restart, regclean, installed the app
we did a reset and uninstall/install of onedrive app