Ah, got it! I thought it was an issue with the nav, since the engine do have them at times. Or maybe I just suck at doing nav meshes, haha! At least I found the hidden gave entry, I'll take that as a win!
Good job! :) And no your right nav can be strange :DD
But yeah you're also right I just tested and if you activate just one lever you can walk a bit on the emptiness so that can be confusing :PP