Sinking spire no entry for next level of the map

I've started the sinking spire map which normally have 3 level and on the first level of the map there is no 'stairs' to reach the next level.

bug report 1.398.711.584





https://imgur.com/Utt78ur

EDIT: I restarted the map but I lost my grand project since the map was already attemped. On restart the stais were there.