I downloaded 18.3 literally a day and a half ago. The fact that in that time you uploaded 2 minor versions is seriously impressive.
I found a small continuity error/bug. It is possible to complete parts of the "teach me" quest (specifically the last 4 stars) way before it's assigned. It just shows the notifications that you compeleted a part, it's not visible at that point. After the quest is assigned, the last 4 stars are completed and I just needed to do the first 3, after that it's completed and I assume it's fine afterwards.
I didn't think to keep note of when exactly it happened or details, so sorry about that.
I think it was after Sarah was punished and I did a couple of quests for the other girls, I found Sarah at the pool and she had a dialogue about training, which finally resulted in me being able to call both Sarah and Alice from my room. Again, I don't remember the exact sequence of events. I have a save, in case it's useful.
Also, for whatever reason, the game resets the resolution when it opens.