Product: The Sims 4
Which language are you playing the game in? English
How often does the bug occur? Every time (100%)
What expansions, game packs, and stuff packs do you have installed? All
Steps: How can we find the bug ourselves? Place a roof and adjust its curvature (you don't need to press SHIFT+C - just adjust pre-existing curve points). Now press SHIFT+C. The game will display additional curvature points but at the same time will reduce the curvature you have already set. Press SHIFT+C again and the curvature is further reduced. Continue pressing SHIFT+C and the curvature will eventually be completely eliminated.
What happens when the bug occurs? Roof curvature (when already set) is reduced.
What do you expect to see? SHIFT+C should only enable or disable the display of additional curvature points; pressing SHIFT+C should not change the roof's curvature.
Have you installed any customization with the game, e.g. Custom Content or Mods? Never used.
Did this issue appear after a specific patch or change you made to your system? Yes
Please describe the patch or change you made. New in the 11/7/17 patch.
Below is a video of the curvature in action - each time you see a reduction in curvature, I have pressed SHIFT+C.