iPhone 15 charging problems

This just started today. My new iPhone 15 will sometimes not charge. I tried googling what was the issue but none of the things stated were my problem. The port is not dusty, the charger is not faulty, I've tried changing outlets and swapping out chargers, but sometimes it just won't charge. And it only does this when it is really low on battery. A few hours ago I had to restart it at 7 percent, turned it back on and it was at 4, then it started charging. Just now it was at 2 percent, I restarted it and it turned on at 1 but it still wouldn't charge. When it died I tried charging it and turning it on but it kept putting the symbol that it needs a charger. It finally turned on a minute or so ago but once it turned on it immediately got extremely hot. What's wrong with it??