Rajesh859 replied at 2019-04-22 22:50:36
Same here bro....i am also getting the same issue....i visited service center they replaced my sub b ...

Its with the update and not the phone's hardware. I am 100% sure in this since it gets fixed if I degrade to 10.2.3 and the issue only comes back with 10.3.4 or beta updates. Before 10.3.4 this issue was not there in any stable update.