Fenix TK35UE v2 battery usage

[Brigadier]

Seems my TK35UE v2 runs one battery at a time instead of pulling off both 18650s at the same time. I will run it until the charge indicator says it is time to recharge the batteries, but when I put them in the charger, one battery is at 3.6V, the other is at 4.0V. And if I put the 4.0V battery back in the light solo, the battery level indicator shows solid green, and it runs at all levels, even turbo.

Batteries are Orbtronic 3500 mAh IMR 18650s. I tried a couple different pairs of batteries with the same result.

Any thoughts?