I have Anki on my iPhone and my laptop, and I recently tried to synchronise from my iPhone. I got a message saying that the decks weren’t compatible. I tried to upload and download, and to check database and backups, but nothing worked. Lastly I tried to uninstall and reinstall the app, but when I tried to connect to my account I got this message:
Error
corrupt:TEXT value in notes.sfld
If you have data on your phone that you don’t have on your computer, you can transfer the collection manually to the computer: Collection Transfer - AnkiMobile Manual