Re: Sims 4 Game settings return to factory default..
@Mothcat182 Are you losing any other files, for example saves? I ask because there are two common and completely separate problems that sound similar to what you're seeing, although I can't tell for sure from your description. Those problems are antivirus and OneDrive, and each has its own master thread:
https://answers.ea.com/t5/PC/CURRENT-ISSUE-Anti-Virus-blocking-User-Folder-Screenshots/m-p/9572695
https://answers.ea.com/t5/PC/CURRENT-ISSUE-Sims-4-saves-user-content-disappearing-PC/m-p/12475370
Mods being corrupted but still present makes me think antivirus, but if the mods are getting renamed, that would likely be due to OneDrive. The event rewards data is stored in UserSettings.ini, which could be deleted (OneDrive), or the game could be blocked from making changes (antivirus). The same goes for Options.ini, which stores in-game options.
You should be able to repair Sims 4 rather than reinstalling it.