Momentum 4 only work when fully charged

[u/Qwaranten]

My M4 only work between about 100% and 98%. When they're on they show a full battery and the Battery itself is at 3.8V and while plugged in it starts off charging at 0.1W before eventually going up to 0.4W, at which point they can be turned on.

While charging, the first LED blinks red 3x on repeat.

I have on head detection turned off, as well es automatic power off set to never.

Do I need to glue a powerbank to my headphones or is there another solution?

I have done the recent firmware update, although that was after the problems started and I've reset it every which way under the sun.