My wife plays DayZ on my PS4, before today there was no problem with her picking servers and playing, but for some reason she can't log into a server to play today (she went to my account and found that she could play on mine so it's not a problem for me who purchased the game). We made another account to attempt it again and the new account also couldn't log into a server, so it seems to only be the secondary accounts on the PS4 that are having this issue.