Yeah it seems if you turn OFF Cross play on PS5 and then try to use the same account on PC you wont have a a very good time finding a match. It'll just sit there until you turn ON Cross Play via PS5 if you go back on PC.
Very Bizarre, i don't really play the game much because honestly I just don't enjoy WZ2 that much but there isn't much else to play, I'm hoping they bring back Plunder..it seems us plunder players have been totally forgotten about, Which is very frustrating because i grind that all the time back when they wasn't faffing about keep removing it in WZ1.