iPhone x reboot when battery percent change

Hello. iPhone X came to me for motherboard repair (microsoldering). It has dropped to the floor and it constatly rebooting, apple logo appear for a couple second and then it rebooting and same continue until battery is dry. I started this repair with power supply connected to the iPhone and the same thing, rebooting, iPhone not going furher than apple logo then after couple seconds rebooting. So, I found out that when I unblug the charging port from the board iPhone rebooted normally and I noted that someone has tried to make factory deafault settings to it, so it started to finishing it (apple logo with loading bar). I waited and it finished the factory setting and ”Hello” screen appeared. At his point I turned it off and connected the charging port flex (same port) and it started doing exact same thing as before, constantly rebooting and cannot managed the way up to ”Hello” screen. Then I plugged a new charging port and connected it to computer, no broblem so far, I set it up as a new device and noticed that in some point it rebooted, but it rebooted all the way to the lock screen (so no stuck to apple logo anymore). Now I have been watching it as it rebooting after about every couple of minutes, then I realized that it has to be related to battery percentage changing. Every time it rebooted in cahrger it show + 1-2% more battery. But it charging atleast. No knocked components around battery connector. Is it hydra or something I don’t know yet. What you think?

EDIT: Problem solved! This was strange

but charging flex had short circuit and at least the microphone has smashed so.. when I replaced the charging flex cable the it stopped the random rebooting.

Kind regards

inspiraattori