Console sharing Issue?

I wasn't sure where to post this but it would make sense to post this here so... me and my friend are sharing an account from another friend because we both don't have PsPlus. Everything was normal until suddenly only one of us could enable our friend's account (Like if I enable the account of our friend then on the other friend's ps it would be deactivated automatically). But the strange part is, I can still play the games from the friend I share the account, but I don't have acces to psplus...?

(I hope you get what I mean, I'm not really good at explaining it.)