Why is my iPhone starting to heat up when I plug in a new battery?

Hi all, I have a problem with my IPhone X. It wouldn't turn on after overheating. This happened after I tried a few power adapters plugging in and out to test the plugs/cables (not clever). So it overheated - became extremely hot and I struggled to hold it then I put it out in cold weather and it cooled down and would not turn on. So I decided to change the battery, I have experience in taking phones apart so it wasn't an issue. I stuck in the battery and when I reconnected one of the battery plugs it immediately started to reheat on the right by the power button components - it seems that the phone isn't dead entirely. Would it be worth for me to replace the power plug ( charging port) or anything else?

I will leave it unplugged for now as I know it is a hazard. Thank you!