We found a Solution to it:

Disable all of your other Addons, except the Maps you want to play on and this Addon, then it should work fine!

Ah, the classic issue of Garry's Mod resulting in unexplainable bugs, that also unexplainably gets fixed by just disabling random addons that should have zero impact on the game. I get so many of these, and I can never fix them because they're not my code's fault.


Anyway, to help identify problems like this, basically: My code will restart the round whenever "Player Initial Spawn" runs and there are more than 1 player in the server. Player Initial Spawn runs whenever a new player joins for the first time.

Some addons can prevent this code from running, if they also use Player Initial Spawn for something, but actually return a non-zero value, which blocks ALL other code on this event from running. That includes the gamemode. So think about which addons you have that *may* have something to do with players spawning, and try and disable those first.

If it doesn't work, disable ALL non-map and non-gamemode addons and try again with JUST the necessary addons.