It isn't a known issue and I just tested it here on the exact firmware without issue using Xerox Mobile Link version 2.1.00.1466 on Android 7.1 (Google Pixel) and Android 6.0.1 (LG G4)
I'd guess you didn't actually enable MOPRIA, or have a router blocking mDNS/IPP
I am trying to use the Xerox Print Service on Android to print to a WC 7225 with software 073.030.126.28110. The message that shows up is "Device is not Supported" whether I try to search for the IP address or use the QR code on the machine itself. I know I am on the correct network as I can get to CWIS on my phone by typing in the machine IP address. I have also connected to other printers at a different location with no issues. I would like to know if this is a known issue or what the next step may be to resolve this. Thanks.