I went back and retested this. And got the same behavior as you did. I didn't test before with the upper curved room offset, only stacked one on top of the other. I think it is probably something not that was intended by the devs. It certainly is not something that I would expect to happen while building. Until it does get fixed, I think you can get around it though, to get the look you are going after.
Hope this helps.
Additionally write (August 17, 2022); Add that I learned the following, including possible workaround, when I verified the glitch that happened on the 2nd floor.
If changing fence to curved wall, the fence is perceived to be in the lower half of the wall. As a result, windows cannot be installed in the lower half.
And this glitch does not seems to be affected from the changing in foundation height, but is a glitch of the curved wall itself.
Tried thing;
Built the room-A, deck-B, and flat-C by round and square platforms, respectively, and change the decks and flats partially to full-walled and attached the windows. (cf. below pics)
In short, when change the fence to the curved wall, the curved wall does not function as a full wall.
What's known now;
There are two causes of changing the range of window attaching.
1. Change the foundation height with the same size round room on top of the round room. (Only happen at ground floor)
2. Change round deck fence to full wall. (Any floor else happen)
Workaround in the case building / renovating (Result tried to verify in vanilla game);
Workaround for No.2 is reloading the lot after change from fences to wall.
Reloading the lot seems to be recognized as a wall.
@rlc77 wrote: "I think it was the second floor or maybe the third floor. It was one of the curved windows that came with the high school pack."
In rlc77' case, No.2 may be the cause.
Workaround for No.1 apply the workaround for No.2
Change the wall above the window that happened glitch to fence. Even though change to wall again, the range of window attaching work correct until reloading the lot.
Workaround No.3 : in the others case (ex.when down loaded the house from gallery)
Try to go out to "world management" and to reload the lot. (add August 18)
@crinrict I have found that it may be a workaround, so I will let you know. However I found it appears that the change in foundation height is not the only reason for the inability to replace the windows. Can I adjust the title?
