I had this same problem last night.
Tello slammed into the ceiling 3 times and wasted one of the motors. It also would not hold altitude and would land on it's own. Reset everything and tried flying with just my phone, seemed to work fine. Next I turned on the repeater with just my phone, worked fine. It would seem to me the fly in the ointment is the
T1D but I will have to get my
Tello up and flying again to be sure.
edit: It didn't matter if I used the stock
Tello app or the
Tello FPV app but I didn't notice any of this until I installed the
Tello FPV app. Not blaming the fpv app but maybe there is some conflicting code on my phone somewhere.