Can't join friend in game

[jagged dew]

(ps4) Trying to join a friend on multiplayer for the first time, we've both made it far past the markers of plauge mission but niether one of us can join.

For my friend it just says session has ended and for me it just loads for a bit and then stops
Sometimes I join where it says we're in the game for a second but then kicks me out and says "Connection to the game session could not be established."
But even that has happened like 2 out of 10 attempts including both of us restarting our games

We've played other multiplayer games together without issue and I've googled to absolutely no avail.
Thank you for your time with this issue

[rose goblet]

Make sure you both have a good internet connection, and set both privacy to friends only

[jagged dew]

Internet connection is as good as can be
Although if it's as stable as it is normally to allow for multiplayer would that affect anything?
Beacuse my wifi isn't top of the line but it works with basically all the multiplayer games I can think of

Edit:
Or am I just out of luck until another wifi company decides to give us coverage with better speeds?

[rose goblet]

No idea i use cable cuz its steady, wifi varies hard, one time good connection other time bad connection

[primal dawn]

Are you both on Ps4? Because it doesn't support crossgen yet.

[jagged dew]

Yes we are both on ps4

Or were, it has been a little while