I can't join parties even though everything else works

I can connect to PSN, I can play online games, but I can't join parties. My friends in the same area as me can join parties but I can't. I recieve the invites straight away, but when I try to join, it says

"Cannot connect to the server within the time limit. There might have been a problem in connecting to the network, or Playstation Network or the server of the service provider might be temporarily busy. (NP-31952-0)

I have good internet connection but I can't join parties, basically. Have tried turning everything off and on again. The only possibility I can think of is that I just got a new laptop and the antivirus on that has a firewall which is now trying to block Playstation? But that doesn't seem right to me. Anyway, if anyone can help with this issue it'd be greatly appreciated.