Sandeerrss, Feb 11, 2019 : Recently I've been missing calls as they ring through to my device. My ringtone will start to go off, like someone is calling me and I can even unlock my phone but the answer and sent button do not show up, nor any other UI popups about the call. It's happened a few times in the past few weeks and today I actually missed a call because of this error. As far as I know I'm updated to the most recent OS for Android that the T-Mobile varient will support. Any thoughts? Clear phone or dialer cache?