I read on the Sony website that if you buy a second hand PS4 that is banned you cannot get it unbanned. You need to contact seller for help. I guess the new account, new IP and location could be the banned owner moving house not selling it. Is there anything that can be done?

I'd take it it's just from playing stuff that would require online play. Say, Fallout 4 would be open to me, Fallout 76 wouldn't.

Would using a banned PS4 put my account in bad standing? I don't have an account yet, Say I buy a banned PS4, make an account, play for however long then buy a PS5, for argument sake brand new. I'd take it my account wouldn't be banned and get the new PS5 banned because it was associated with an account on a banned PS4. Or get the PS5 onto PSN but in bad standing, not banned but thought to be a trouble maker.

Also should I ask WHY it was banned before buying?Some activity it could be banned for could be worse than others.