I don't know if this is normal, but whenever I get inside of a Dungeon, I always get soflock whenever I have several party members and I have already passed that "point", if I just so happens to try to go back and the party member is in the way at my back, then I automatically get soflock. I don't know if it is because the only way to advance a dungeon is to always go forward, and then you cannot explore all the dungeon.
Hey there. Sounds like you may have encountered a bug. Which version of the game are you playing on?
And the dungeon/floor that you got soft locked?
For some dungeons you can only move forward, up, down and cannot move backwards. (This only applies for the first few dungeons). Intentional for choice pathways and decision making. Theres is also an arrow movement legend/indicator on the bottom right of the dungeon level that highlights and indicates allowed movement.