Notes appears to be corrupted

Hi nanonanorats,

Thank you for using the Apple Support Communities! We understand you are able to see all of your notes from other devices, except your Mac mini. On your Mac mini, you're only seeing one folder. We know just how important it is to recover your missing notes, and we will do our best to assist.

To answer your question about if you can uninstall and reinstall the Notes app. You can, however, you would need to reinstall macOS to reinstall any deleted built-in apps: How to delete apps on your Mac - Apple Support. We don't think you'll need to go that far, however. Instead, please continue below.

Since you mentioned you can see all of your notes on your other devices, this would tell us that you are using iCloud to sync your notes. The first important step to take, would be confirming if you have the right accounts selected for the Notes app. To do this, open Notes > Accounts. Then, make sure you have notes turned on for any account you recall them being saved to, especially your iCloud account: Add or remove accounts in Notes on Mac - Apple Support. You can even then, go to Notes > Preferences > Default account, and make sure you have your iCloud selected there.

Let us know if that works out for you.

Regards.