Our Office 365 accounts are in an ADFS Federated .GOV Domain but our Computers are Joined to a .COM Local Domain that is connected to a separate Azure Account. Lately we have been having numerous problems with Outlook mainly after the user changes their passwords. Shortly after changing the password Outlook prompts "needs password" (which is totally expected) but when you try to login the Office Login has the Local Logged in User's .COM credentials prepopulated and requesting a password? When we click the Use different account we are able to enter the .GOV username which immediately sends us to the Federation Server where the login is promptly rejected as it seems to be holding onto the .COM credentials even though we attempted to change it? Our Department does not have access to O365 Logs and such but we have found that when prompted for a Username And Password if you enter a wrong password you are prompted again but in this situation you are not prompted for a password at all except with the prepopulated .COM credentials so we are pretty sure the .COM credentials are the ones being presented to the Federation Server which promptly rejects the login with an error about Your account is not authorized. Access Denied.
Normally if we try several times eventually we will get a popup window requesting email address AND password and the problem will be resolved until the password changes again but other systems only show the Office 365 window with the prepopulated .COM account looking for a new password.