Stuck on 'Downloading game settings.'

[MDS_R4]

Hi guys.

When I connect to the PC hosting the custom game (zombies) the window 'Downloading game settings' remains in front. It never goes away.
I can see in the background the other player's movement, but I never get to play in the actual session.

All my ports are correctly forwarded (3074, 4976...) and I allowed Plutonium in the Windows 10 Firewall.

Any ideas? Thanks in advance.

P.S.: I also note that in one of my PCs, when I'm done playing in any server and return to 'Public Match, Solo Play, Custom Games...' menu, THE VIDEO LAGS (mouse, key pressings, background animation). This is not happening in my laptop, which has an inferior video card.

[LMAO_BALLS]

MDS_R4 If you have the solution please tell me I have the exact same issue and I've tried fixing it all day.Please help.