@delaney75 Malwarebytes didn't find anything, which is of course good, but it also means the Sims 4 issue and the dxdiag crashing are unexplained. So I would suggest running a repair install of Windows. But before proceeding, please make sure you have enough space. (Your dxdiag would normally report this, but the information is missing from both files due to the crashes.) Open a File Explorer window and click This PC, and you'll see the free and total storage for each drive. If you see less than 25 GB free on C, you'll need to clear more before running the repair install.
If you have enough space, follow this guide:
https://www.elevenforum.com/t/repair-install-windows-11-with-an-in-place-upgrade.418/
This shouldn't delete any of your data, but if you get to step 14 and are NOT asked to keep personal files and apps, back out and start over.
Once you've run the repair install, try again to play. If you get another crash, create a new admin Windows account and try playing in that. If the game crashes yet again, please run a new dxdiag, which will hopefully contain all the relevant information.
Just in case the new dxdiag is missing some info, please list the current free and total space (check again after the most recent crash). Please also look for new errors in the Reliability Monitor. Hit Windows key-R and enter "perfmon /rel" without quotes, and you'll see a chart of errors and updates with a column for each day. Today is on the right.
Look for an error that happened at exactly the time of your most recent Sims 4 crash, specifically in the new account. If you find one, double-click it to see more details, then copy that info and paste it into a reply here. If you don't see a new error, check back in an hour or so—the Reliability Monitor doesn't always update right away.