outlook repeatedly asks for 365 credentials

We have a new RDS solution so user profiles newly created etc.. AD environment with two session hosts, profile disks and a broker server. Since we have used this solution outlook repeatedly asks for 365 credentials. This is happening for all users at different intervals. Some get asked every time they log on others could go several days without incident. I have ran office repair on both servers, recreated profiles, tried several reg entries but nothing seems to change this behaviour. Sometimes we also get the 1001 something went wrong error and user has to sign out of RDS log back in and re-enter credentials. Any help would be greatly appreciated.