A rubble pile (00044EDD) is invisible. I checked to see if it was disabled and that isn't the case because you can run into it. This was the second time I went through the dungeon. It should be noted that the dungeon doesn't reset. I had already cleared it out previously, but had to go through it a second time to reach some locations up above. I'm somewhat sure that it wasn't invisible the first time around, so this could be some kind of engine nonsense. The only thing I can think of to check for is for a room bounds issue.
Screenshot:
https://postimg.cc/YjjB3p6r