See, Peter...oh sorry no, I see, you have no idea of how powerline works, right? Otherwise, i cannot explain myself why you are posting such words in my direction :-/ Me (and others too) tested more...

Activate "Lower PLC-to-VDSL Interference Mode", do a power reset on all adapters and check connection again,,,

There are no single adapters on the market, i was in same situation and bought additional kit :-/