Notes missing on Mac after toggling 'sync to the cloud'

I was having an issue with several of my notes not syncing between my Mac and my iPhone. One suggestion was to toggle "sync to the cloud" off and on. I did this and immediately all of my notes on both devices disappeared. However, when I looked at the contents of icloud, it showed that 1.4GB of Notes data was still there. After about 10 frantic moments, the notes began to reappear on my phone, and are now all there. However, there are no notes listed in the Notes app on my mac. I have tried restarting the app and rebooting, including in safe mode. Both devices have newest public versions of MacOS and iOS.

Any ideas on next steps?

[Re-Titled by Moderator]

Original Title: Notes on Mac disappeared