Gear up ...
StrangeOkay. But battery lasts long like it used to. no quick discharge or quick charge.
Maybe I found the exact problem. It's speaker.
When I set speaker volume to zero and play any Video or Audio or Game or App, it does not restart.
But when I set speaker volume to max, and play any Video or Audio or Game or App, it restarts without warning.
Maybe it's speaker fault or dirt and dust in it causing issue.
And for custom ROMs I need to check that again..