Hi s33ty23,

The problem (at least on my phone) is related to the connection between the battery and the phone pins. Apparently, the space where the battery is located is just a little bit bigger than what it’s supposed to be, and the battery slides just enough to break the connection to the pins.
Easily solvable by inserting a little something below the battery, to push it up a bit,,,,,,

good luck with your fix,,,
have a nice day,,

Regards
Arul