Yeah, the compiler has always been a little confused as to the exact meaning of adjacency- I didn’t dig into the I6, but I noted this in my treatise on spatial relations:
Adjacency A room is adjacent to another room if it is possible to move directly from one to the other by a mapped direction- perhaps surprisingly, 2 rooms connected only by a door (regardless of whether the door is currently open or unlocked) are not adjacent to each other. Although the documentation states that adjacency applies only to two rooms, possibly as a bug it also sometimes applies to a room and a door, but that fact probably shouldn’t be relied upon. As a convenience, the adjective ‘adjacent’ applies to any room adjacent to the player’s current location.