I just tested it and if I hold it to power on the phone it doesn't flicker anything what's so ever it immediately brings up the Google logo and powers on as normal. Only the quick tap causes that power flickering.
I think I'm going to open a ticket with Google so it's on record Incase it is a hardware issue so I can get a replacement. Hopefully it's a software/firmware fix is all that's needed. Either way since I'm Fi customer and purchase from the Google store they always send me the replacement first and only then I need to ship the defective device back so I'm not sweating it. Especially with all the backorders and stuff this issue does not effect anything I so but regardless I want a new device if it's a hardware issue.