When the phone is locked or the screen is off, incoming calls will ring / vibrate but there is no way to answer the call. Even unlocking the phone and going into the Team app doesn't activate the dialpad. Eventually the call goes to voicemail and a missed call notification comes up. Have tried deleting and reinstalling the app but no success. This seems to have been an issue for some users last year looking at earlier posts.
Teams app version 1416/184.108.40.2069090401 on Android 9 Pie.