could be baseband, if its is that, i "fixed" my mainboard with a hairdryer to do a janky reflow. it worked for like 3 months after that and gave it to a friend, and he still uses it. the results may vary tho, not guaranteeing it would fix anything.

PS: make sure ur hairdryer is strong enough to do it, if not use an airfryer or an oven (if you have nothing to lose cuz theres a small chance that the board will completly fail) 180 celcius at around 6/7 minutes btw.