Hi Walter,
Nope
I started out with everything working with an ethernet cable between the modem and the switch.
At this point the 2 powerline connectors were plugged in and switched on, but not connected to anything.
I unplugged the cable from the switch, and plugged it into 1 powerline connector.
Then plugged in another cable between the other powerline connector and the switch.
Mouse OK, keyboard frozen. Connection to Internet was still OK.
Reverted to original cabling fixed it. Tried this several times.
Maybe I should bring things up gradually. Will try sometime.
A couple of days ago was experimenting with a couple of borrowed Zyxel G-570S wireless access points, instead of the powerline connectors. One was only about 1 meter away from the keyboard, and caused it to become a bit iffy - sometimes the keys didn't respond. Turning down the output power to min on the Zyxel largely cured that problem.
Cheers,
Peter