"Objects" setting texture changes

ukbucket​  It looks like you have two new graphics driver errors since your last dxdiag, which is fine if they've stopped since you switched to DX9 mode.  I do think you should be able to play on DX11 mode and on ultra settings, but if you're satisfied, that's what matters.

Is it possible that your GPU is overheating with the higher workload?  If you're curious, the Task Manager's Performance section can give you a rough idea of how hot it's running.  A modern graphics card will start to throttle above about 70º C, but anything under 80º is still fine.

If this is the issue, it may also help to manually limit your in-game framerates.  Your monitor is running at 59 Hz, therefore it's not going to show any extra frames above that.  You could therefore limit fps to 59 without impacting performance on a practical level and while also giving your GPU a lower workload.

There are a few ways to do this, but the easiest one is to open Options.ini, in Documents > Electronic Arts > The Sims 4, search for framerate limit , and set it to the limit you want to use.  It's fine to play with this number a bit if you're getting graphical glitches at a certain value.  And you can also change this limit even if your GPU isn't overheating—it's a useful test given the other issues you've reported.