Despite extensive googling and a support call with Microsoft I've yet to find a solution to this issue.
Azure AD joined machine - account Active Directory Synced to Azure AD.
If an account is added to AD FS Staged Rollout group to move to cloud authentication then after a few hours or an hour the computer becomes unusable until a reboot. (Teams disconnects, Outlook Disconnects, won't unlock etc)
There are 2 other users who have the same config yet not experiencing the issues.
If anyone has any ideas what the cause could be would be great to hear - many thanks