Every day our guest users get locked out of SharePoint, receiving an access denied error message. After a while, minutes or hours, the problem goes away and they can access normally again. Some weeks it happens at 9am every day, and some it increments by an hour daily (9am, 10am, 11am…) which indicates some kind of scheduled event on the backend. We did find a workaround after the first couple weeks; sending an invite to any existing guest users, with or without email notification, jiggles something loose and restores everyone’s access.
This has been ongoing for weeks, with open MS support tickets sent but no solutions found. Support doesn’t know, the engineers think everything is fine, and I can’t find relevant incidents online. Anyone have any ideas?
