Same issue here with Epic version. Crashes immediately upon showing the starting dialog window in multiplayer. I've played single player for quite a while with zero issues.
I've run through every fix in the FAQ. Uninstalled/Reinstalled multiple times. Verified install. Ran Epic as admin. Ran the .exe as admin (immediately after clean install). Tried every size universe. Turned off cloud sync. Deleted all the files from previous installs (per the guide in the FAQ). I don't know what else to do. All my drivers, Windows updates, and Epic Store updates are up to date.
I've *never* had connectivity issues in multiplayer games with the person I'm attempting a co-op game with. Our PCs are near identical and wildly over-spec'd for this game (both running i7s, 32gb RAM, RTX 2070 Supers).
Is there a patch or fix for this in the works?
Every thread/post I've found regarding this issue seems to end with no one finding a working solution.