I had the same problem. I even disassembled the charger but i could not find the problem other than i thought it must be corrosion. I bought a fiberglass brush and cleaned the pogo pins on the charger and on the headset. Then I cleaned the contacts on the batteries.
That’s it. Now it’s working :D
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Edit: You should be able to clean the pogo pins of the charger without disassembling it, through the battery slot.
I had the same problem. I even disassembled the charger but i could not find the problem other than i thought it must be corrosion. I bought a fiberglass brush and cleaned the pogo pins on the charger and on the headset. Then I cleaned the contacts on the batteries.
That’s it. Now it’s working :D