Your Proof of Identity might have been rejected due to the following:
1. The scan of the document is cut and not all 4 corners are visible.
2. A certain area of the ID is not visible.
3. The quality of the scan is not sufficient.
4. There's a glare, a part of the scan is blurry.
5. Your proof of identity is out of date.
6. There is no expiry date on your proof of identity.
Please, make sure these guidelines are followed before submitting your KYC scan.