Notes

To find out if it's system wide or user specific, try this...

Open System Preferences>Users & Groups, unlock the lock, click on the little plus icon, make a new admin account, log out & into the new account.

Does it work in the new account?

Quit Notes, Quit System Preferences, try trashing these 2 files...

~/Library/Containers/com.apple.Notes/Data/Library/Preferences/com.apple.Notes.plist

~/Library/Group Containers/group.com.apple.notes/Library/Preferences/group.com.apple.notes.plist

~ tilde indicates hidden Home Library.

Apple hid the Users' Library folders...

Method 1:

1. From the Finder, select the Go menu at top of the screen, and choose Go to Folder.
2. In the window that opens, enter ~/Library, and click Go.