Mitel has corrected this issue and revised R1807 build 21.90.4128.0 contains the update. The new build and patch file are available for download. The patch file is only required for systems that have already upgraded to R1807.
In MiVoice Connect R1807-PREM build 21.90.4127.0, incoming calls over PRI or E1 trunks that do not include a Caller ID Name in the ISDN message fail to ring 400 Series IP phones. These calls are forwarded to the No Answer destination. Calls to legacy MGCP phones ring and can be answered, but no information is displayed on the phone screen.
R1807-PREM is temporarily unavailable, and the corrected full build is targeted for availability on the MiVoice Connect software download page on or before November 14, 2018. If you have already upgraded to Build 21.90.4127.0 and are experiencing this issue, a patch file is available to correct the problem. Email email@example.com to receive the patch.
R1807-PREM build is being pulled due to an impacting issue affecting customers with T1k, E1k, 220T1 and 220T1A switches and using 400-series phones. There should be an updated version of the R1807 build released within a few weeks that addresses the issue.