Blender 2.8 was published lately while our game production on Kordex. I modeled already a pretty huge part of the cave level in Blender 2.79 and need to continue with Blender 2.8 now. But I hit at this problem and want to share my solution with you!
Those greyed out collections annoyed me a lot because I was not able to enable the visibility at first. Hope I can help you with this information!