"Objects" setting texture changes

ukbucket​  Your dxdiag is full of crashes of the graphics driver.  I don't think this would be the direct cause of what you've described, but the issue should be addressed regardless.  And if the driver is the cause of the Sims 4 issue in general, reinstalling it should help.

So please do a clean uninstall and reinstall, as described here:

https://crinrict.com/blog/2019/02/clean-re-install-of-graphics-drivers-with-display-driver-uninstaller-ddu.html

I will say though that there's no reason your computer can't run the game on ultra graphics settings.  If the GPU is a bit hotter, that's not necessarily a bad thing.  If it's actually overheating, say, if it gets to 80º, then that's different.  But in that case, I'd suggest checking the GPU's fans and the case fans as well, since Sims 4 shouldn't be able to push this graphics card all that hard.