Movies watched synced okay from .csv file, then they disappeared after i made some edits

I successfully imported 951 movies watched from the csv file. I was able to see them. There were some errors at the top so when I removed just three movies and re-added the correct ones, all 951 movies disappeared and I cannot figure out how to see them. I tried re-importing the list 3 times and they just appear, then disappear, every time. Is there a way to fix this without uninstalling and reinstalling the app?