Plutonium

I'm looking to play zombies with 5 people and discord says its 4/8 in lobby so can i join a full lobby somehow? any help is appreciated.

Hi, me and my friends have been trying to get custom games to work for an hourish now and im getting real pissed so i decided to ask here, i have 3 other friends i am trying to play with Starberry,Panda and Sakuya, and we keep getting an error that says "Error unable to join game session", i am able to join starberry and he can join me, panda cannot join starberry but starberry can join him, i cant join panda, sakuya cant join anyone and nobody can join him, we have all enabled it on our firewall and sakuyas nat says strict but all of ours say moderete, I've been told to port forward but we can join certain people so i dont understand why that would change it at all. Thanks for any help i can get