I've tried reloading it a couple times from different saves. On my way back from retrieving the item (when Nao collapses and movement is slowed), I can pass through the door after the first chessboard, but not the second. I have tried everything I can think of, but it's acting as if it's just a wall. I noticed this glitch in the blacksmith's building on the same mission as well. I was unable to exit the room after looting it, and I had to restore from one of my previous saves. Is there any way to get around this one room? If I'm the only one having this problem, I would be fine with just using a cheat or something to bypass this.