this a known issue and its very network dependent.
for instance my map will go for 5 seconds then desync the host, other times it crashes immediately upon entering the map, sometimes after hosting it once it doesnt crash at all, but only if 1 other person networked into the server the first time it was hosted. subsequent times with the same client instance it will be stable. its the maps configuration has to be very very precise but then again why does it work fine the 2nd time around on the same client?