Grounded Login Problems on PS5

Just wondering if anyone else is having major issues Loging into Grounded on the PS5, but If you do manage to log and try and connect to a friends game via an invite, most of the time it doesn't work. I live in the UK and my friend I've been playing Grounded with lives in the Netherlands and we've been playing it every weekday night for over 2 months now without any issue (We're both on PS5 btw). Since Monday 17th March I've been having really bad problems trying to Log into and play the game. Last night it took over an hour for me to Login and eventually connect to his game. Once you're in, its fine! I have tried everything from reinstalling the game, deleting the game date on the console, trying to open ports on the router, using a dmz connection etc etc and nothing is working. We've tried various other games and they work fine, there just seems to be something wrong with Grounded. He on the other hand has no problem in Loging and playing. I just can't work out whats wrong, I've even logged into my Mircosoft account thats linked to my Sony account and it all seems fine. Is anyone else having the same problems and have any fixes they can share? Many Thanks!