@PDXJD I couldn't find the link again, but when I was researching this I found an article show technical electrical things I kind of understand that showed how surge suppressors can block the frequency that powerline runs at, and I found articles that said it might work but performance would be impacted to varying degrees. It sounds like it depends on how a particular surge suppressor works. I had a small APC battery backup surge suppressor and a heavy-duty one I took from a datacenter we shut down and the P9 wouldn't work on either of them. I'm in an older house/apartment so I'm plugged straight into the wall to get maximum performance until I can get the landlord to let me make some holes in the floor to run ethernet through the basement.