We acquired 8821 phones but their performance is lousy, after configuring and delivering them to the end user they report that the phone does not work, the phone is connected to the wireless network but it is not registered, we have to restart the phone so that it can be registered but everyone The same thing happens to them every day. We have AP meraki MR52 with excellent coverage, the CUCM version is System version: 11.5.1.10000-6
Firmware version of 8821 phone is sip8821.11-0-3SR6-15
