iPhone 8 bootlooping when plugged in, no power otherwise

Yesterday my iPhone 8 started behaving poorly. I saw that the battery was critical so I plugged it in and it vibrated, but the battery symbol never showed that it was charging.

When I got into the battery settings, it said it was charging on 1% and it was occasionally restarting itself.

I left it alone and eventually it started charging like it was supposed to so I thought all was good and it was just being weird.

Now today, it’s not turning on and boot loops when it is plugged in. I even put it on a wireless charger and same thing. Just an endless loop of white screen apple logo and then black screen. Can’t connect it to the computer because it never gets far enough to be recognized as plugged in.

Once I unplug it, it’s just dead.

When I was able to get into the battery settings, it said it couldn’t detect the battery capacity and it used to be in the 90s.

It hasn’t been dropped nor gotten wet. It does get warm when I have it plugged in trying to charge.

So what’s the damage? Bad battery? It was perfectly fine before yesterday then started having charging issues.

I appreciate any advice!