AirPods Pro 2 case won't reset and drains battery quickly

AirPods Pro 2 won’t reset.

When I open my charging case the light is flashing amber and I can't reset the airpods. The problem is that the case is completely discharged after like 2 days of inactivity. I even disabled find my option, but it does not help. I tried the standard factory reset procedure, but I can't get them to flash white.

As soon as I open the case they make a short beep. If I hold down the back button for 15 seconds while the light is flashing amber they beep 3 times, but nothing happens.

The case does light up green after I close it, so I guess it is charged fully. The firmware of the airpods is the latest available. Not sure what else can I do.

Both airpods still works and I can still charge both the case and the headphones.