My tablet only charges while it's off.

I haven't been able to figure out the issue but I assume now it's software and not hardware. My tablet died one night while on a charging dock.

I set it to charge, then I realized that while it's on, the little charge icon shows it's charging even when it's disconnected. However, it doesn't charge at all. I tried using both the charging dock and charging port. I tried downloading 4 different apps to check the voltage, and they all say there's a charge. Additionally, they read that the battery is fine. I tried a different charger and no luck. However, if I turn off the tablet, it'll charge like normal.

I reset the tablet already. I replaced the charging port. Any ideas?