Quote from PortalCombat on July 16, 2017, 3:19 pm

I just want to share this guide and hopefully more people start using the fixed instances:
Steam Guide

I got a lot of people commenting on this bug on all of my maps.
Finally found a way to prevent the bug, without messing up the instance-input/output.

This bug is on each PuzzleMaker coop map, so every mapper should use the fixed instances.