I've got the same issue on the premade house of the Goths. The curtains on diagonal walls (with or without windows) no longer go down with walls cutaway view, because the game considers their placement invalid now. They obviously worked before, because it's built like that in the default house.
Same here. After 1.63 all decor that was placed on diagonal walls prior to the patch, won't go down with walls now. Very inconvenient to play.
And new objects, such as curtains or pictures etc, just can't be placed on diagonal walls at all.
Why can't there be no bugs ☹️....
