On this same tile in astral harbor (it was security vault, I misremembered), tried to walk past this bridge into the room proper and character became fully stuck -- an enemy may have been walking out from the "dark" portion of the room as I attempted to cross, since one appeared/got somewhat stuck just after I realized I couldn't move? (Between waves, was only the monsters that had spawned in this room upon revealing it)  I used the "teleport to crystal" button afterwards and every character was stuck, including all enemies from all spawns on the map, and the crystal bot.