PlayStation 5 Multiplayer Connection Issues...Help???

Hello, fellow little nightmares...

I pre-ordered the deluxe edition of LN3 so me and my friend could play it on release, we were both really excited to do so, didn't realise it wasn't couch co-op but no big deal, he also has a PS5! He went home and downloaded the friend pass, both of us got onto party chat so ready to finally play, I invite him to the session and select my character, screen goes black and...connection error.

This is happening to us on loop, I have tried restarting, restoring licenses, both of our WiFi connections are perfectly fine, and still no dice.

Devastated. 😭

Does anybody have a fix at all? I'm seeing lots of people online complaining of the same connection problems across all platforms but wanted to put this here anyway because Reddit always seems to come through with a solution.

If anybody has one I'll be eternally grateful. 🙏

Thanks in advance, and I hope you all enjoy the game! 💛