I am also having a similar issue adding an Apple Developer Account to VS19 for Mac. I go through user/pass authentication fine (I've tested a bad password, and the error message is different), and then I seem to make it through MFA. VS throws an error: Failed to synchronize ****@****.com account with Apple Developer Portal Your session has expired. Please log in. Your session has expired. Please log in. I have verified that I am an App Manager and can create certificates, profiles, devices, etc. I have also created, built and debugged a "Hello World" application in XCode, though I did not pair it to a device. Any clues would be greatly appreciated.