edwar + mgmmc
Tks for input. Fact is after cable modem providing internet plus tv cable channels, (via 2 x tv boxes)I have installed switch into which both nets are plugged in. So both have same origin i.e. the same switch just behind cable modem. Thereafter, router sits on cat Lan into which I have PC connected via cat.
I fear if I move powerline lan behind router I will lose all cable tv connectivity. Furthermore it would not suit physical layout in house.
I realise an interesting puzzle and appreciate your assistance with ideas for resolution.