Visible part on walls down under window is not same color

All windows have this graphical bug/shadow/off-color on the bottom of the wall when you put the walls down. Even if the room is brightly lit up the issue is still present.

I completely uninstalled my game, Backed up my mods/cc into a different folder. Removed all traces of the game everywhere including removing sims4 folder in my documents and re-installed just the base game with no mods or DLC and a brand new save. The issue still happens.

Video Evidence: https://streamable.com/kp0wn9

Edit By Crinrict: Adjusted Title to better reflect the issue