Thank you for the quick answer. That was my bad - I mainly used the "recommend" gear selection and thus came to the wrong conclusion.
I did solve the tower and then understood the in-game hint. The freeze was painful - I did talk with every maid to every maid - to every town npc - at least twice on two dates - tried to walk every area in case something triggers,... In then end I got it, but I have no idea which steps were actually needed.
Now I am stuck on 19 - blue sparks - which semms to be a non-return trohpy - did check that. I am now about 1+hr in that dimension. I do get the occasional different "spark" dialogue "never", but I have no idea what it means. Idk If I am progressing or resetting, chest keeps moving, sparks stay the same blue. If there is a special order - can´t talk to a maid for a hint, they are not there.