Problems with Surge Protectors

I tried to power on my Oppo the other night in anticipation of watching a DVD. It wouldn’t power on. Not with the remote and not by manually pressing the power button. After contacting Oppo support and following more than the usual instructions to restore process to my Oppo, nothing worked until I was instructed to plug it into a wall socket. After a few days I returned it to the protection of my Brick Wall, a line conditioner and surge protector that cost me nearly $600. It is advertised to never fail

https://www.brickwall.com/pages/no-failures

No Failures - Period | Brick WallBrick Wall Surge Protectors Do Not Fail Tested to One Thousand Surges of 6000V, 

https://www.brickwall.com/pages/line-conditioners

I then brought out an ordinary power strip/surge protector and the same thing happened; the Oppo failed to power on.

Coincidentally,, I bought a new Roku and when I plugged it into the Brick Wall, it failed to display its menu. I plugged it into a wall socket and no problem, it displayed its usual menu. I plugged it into the power strip and it refused to display.

I wrote to Oppo and asked them why they had told me to plug the Oppo into a wall socket. They replied that they had had some problems with surge protectors and didn’t know why.

I also have my ARCAM SR-250 AVR out for service because  among other things, it wouldn’t power on. The service department where I sent it reports that it operates perfectly. Now I’m wondering if it is having the same problem as the Oppo and the Roku.

I should add that I’ve tested all the sockets on the Brick Wall and the power strip and all will turn on a lightbulb and I’ve also plugged in a power saw here and there and the power saw runs loudly.  
I’ve pulled out a third power strip from garage storage and both the Oppo and the Roku power on.  Returning them to the Brick Wall doesn’t work as they again will not power on.

What is causing this problem???