Akobie Nope I have the same problem as Ursegor. Player 2 spawns behind an invisible wall at the beginning of the level.

Ursegor your friend might be going the wrong way

can't play online , my friend is blocked by an invisible wall at the beginning of the level .

the map does lag at the end

i think ur issue is- its quite common is the enemy got shoved in the floor or got stuck knocked down so u should go back and cut off every leg for good measure

massive slowdown on this map too, just about at the part with the spiders.
Also I was very careful about killing every enemy I came across but after killing the boss it said "1 enemy left" I killed the mages all the spiders everyone, I'm pretty sure this is a problem with the base game where it doesn't track how many enemies are left properly so the only way I can think of to fix that is by adding a normal exit.

good map map is good