Opus BT-C3100 v2.2 vs XTAR VC4 charging methods?

Ok, I’m a little embarrased, just ran across 4 threads asking the same questions… but did run across this and haven’t found what the bad behavour is yet:

This from HKJ in
Chole’s review Opus BT-C3100

“I have been testing on this charger the last two weeks (That means around 40 charts).

Most of the time it is ok, but I have recorded some examples of bad behavior.”