What to do if the battery level is incorrectly displayed?

I recently had a problem with my convertible; So a tablet / laptop combo. Windows base, 20H2.

Model: EZPad 6 Pro from Jumper (yo China…)

I'm constantly shown a battery level of 0%, with or without a charging cable. When the battery is charging, the display remains at 0, but the battery is being charged. Gets warm and switches off when full. The device can still be operated without a charging cable, Windows then just annoys you with the message that you have to charge the battery. I once installed Battery Care, which means that the battery is 100% worn out (wear level); if that were the case, the device would hardly work without a power cord.

The registry keys for the battery or power settings should be correct,
Computer \ HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Power.
Didn't find really helpful topics on the web either, mostly related more to the "lost" battery indicator in the tray.

Calibrating the thing with the battery doesn't make any sense either, since the charge indicator always remains at 0%, even when the battery is being charged. (Is it loading? Yes!)

Anyone have any idea why that could be, I'm pretty much at the end of my game.

Take a look at the manufacturer's site to see if there are drivers for your device and update / install them

Already tried the isn 300 euro china device (jumper ezpad 6 pro) and on its driver side it looks cloudy. Even with bios flashes there's more of a vinegar…
that was one of the first ideas i had. Lt device manager is available for the battery and power supply as only the windows driver (ms acpi controller ~ battery / ms power supply). I already checked.