Hello,
My anki desktop application on Mac and my iphone anki app are not matched. I have 100 less cards due on the phone compared to the computer version. And even if I do a card on the phone and sync everything, the phone’s due count will go down but the computer’s due count will stay the same. Everything is as up to date as possible, what’s the problem?
Are you syncing both devices with the same AnkiWeb account? Go to Preferences > Syncing on each device and make sure they are pointed to the same account.
If you have somehow ended up with separate versions of your collection, make sure you follow these steps when you’re ready to merge them, so you don’t lose any data. Syncing with AnkiWeb - Anki Manual