8875 can not register to CUCM successfully

[jiache2]

It could be two reasons. 

1. Unsupported firmware. 

8875 was first released with MPP only in PhoneOS 1-0. Phones manufactured in 2022 come with PhoneOS 1-0 can not recognize CUCM or get registered. User and admin need to upgrade 8875 to PhoneOS 2.0+ to make it compatible with CUCM. See attachment for details. 

2.Impact from FN72302
https://www.cisco.com/c/en/us/support/docs/field-notices/723/fn72302.html

[Roger Kallberg]

You should really post this as a knowledge article instead of as a question.