I bought several Ali Express non-DJI batteries for my Air 1, Mavic 2 Pro, and Mavic 1 Pro in two separate purchases spread out over a couple of years. Those batteries dramatically increase the range of both Mavics from 6 miles round trip, flown...
And then it became silent .... Hi guys! Just opened my case with my MA1 after lying on the shelf since 2018. Used it once for making a video from my house and property. Charging my original battery, now flashing at 2 leds... Interesting.
What...
If I managed to find a second hand mav.2 on .0670 firmware: I'd snap the sellers hand off. Last fully featured firmware on ARB#1 without all the subsequent "security fixes".
Great! That confirms no problem with any of the new batteries, and insufficient power on the hub charger to function properly. You need at least a 30W charger. Double check by charging the third battery in the drone, too.
Except in the video, neither battery is charging. Both are flashing the low power input flash on LED 3 because the OP states he is only using a 20W charger, instead of the minimum of 30W. That's the real problem.