I had a closer look to your code and i think this fonction is not working :
public OnRoundEnd(Handle:event, const String:name, bool:dontBroadcast)
isMapTransition = true;
I think it's not going into the function so the variable isMapTransition is still false
instead of being true
The thing is i dunno if it's caused by the sourcemod 18.104.22.1684 version or if it's not the proper function called ?