Entering and exiting a secret room in Dungeon Mode should not reset the main floor's minimap

If the player has no Map in Dungeon Mode, the minimap slowly builds up as they explore each floor. But if the player finds an enters any secret room, then returns to the main floor, the minimap is fully reset. This did not happen in the original Necrodancer and can be frustrating if e.g. the player found the exit, then spent some time in a puzzle room and no longer remembers where the exit is (they have to find it all over again).