I think this may be a bug with the mobile app. I have many file approvals in the 'approvals' section of the app that I have marked as approved or cancelled already. I checked on my desktop app and they are all either marked as approved or cancelled but they still appear in the 'approvals' on the app. I even went so far as to delete the entire task that the file approval was living in and it's still there.
We use tablets in meetings and I like to be able to look at approvals in-between when I'm not at my desk, but it's frustrating that it doesn't appear correctly.