I've traveled a few times now between the USA and China. Each time I've needed to complete check-in at the airport because the United mobile app does scan my Chinese Resident Permit but refuses to accept it as a valid travel document.

Has anyone had success with this type of travel document before and know of a way to get one scanned and saved to my travel profile so I'm not needing to check-in at the ticket counter every time I'm traveling?

Or is this something that is just not possible with flights ex-USA to mainland China?