Seriously doubt there is anything wrong with those cells. Been using many of those GA’s for a long time. I’d start by getting a better charger. I’ve had mixed experiences with that UM20 flat top vs button tops. Taking too long to charge. Finding a high enough Amp usb wall wart to power it, and not being able to charge an over discharged cell.

The Nitecore D2 or D4 are nice. The Opus BT-C3100 will allow you to discharge, charge, and test your batteries.