I have now successfully completed the identity verification procedure.
It looks like ID verification has only been tested on some cell phones and doesn’t work on any other device.
My experience:
Asusu Zenfone 4 Max - Black Screen, Camera Not Working
RealMe 3 Pro - camera works, unknown error after scanning
Huawei P2019 : success.
For everyone who has problems with ID checker: try any other cell phone. If it doesn’t work with a mobile phone CHF 400, it can work on a cheap device CHF 100 🙂