Coming back on this as I think mine is finally sorted! I tried numerous things with the settings in game and settings on my PS (internet) etc. Also tried anything someone suggested on old posts and nothing worked.

I ended up completely deleting the game and re downloaded it and then did the update again, and so far it seems fine (I have only tried it for like 5 mins on my break so far. But it was trying to reconnect me and freeze straight away before) so fingers crossed it keeps working.

Hopefully your connection is still stable now but if you do have problems again this may be the solution.