When you move to enter certain dungeons on the map, the game will briefly pause or stutter as if about to load you into it, but then nothing happens and you remain on the overworld. a week or so ago i noticed this same bug also occurred for a particular dungeon in the black biome, except that entering caused the screen to dim somewhat (possibly some sort of visual effect that was supposed to apply inside?)
Version 2.0.12 3.07