Where did my Google Keep notes go?

[AC Question]

I synced my Samsung Galaxy S3 to my Google Account. I'm not sure if this had anything to do with it, but I later noticed three years of Google Keep notes had disappeared.

I updated the app. Still no notes. I unsynced my account. Still no notes. I re-synced Google Keep. No notes. I then checked my Google account on my PC using Firefox. Still no notes.

I need them back. Please.