1-way audio and phones losing registration

We are still having issues with this. The last suggestion that support provided was to factory reset the phones. With the number of phones that we have, that is not an easy solution as they aren’t able to provide us with the admin password configured by the RingCentral configuration servers. 

The phones are on ports with VLAN tagging via LLDP. Doing some packet captures, the issue is caused by the phone attempting a connection on the native vlan rather than the tagged voice vlan. After the first call fails, the second call traverses via the tagged voice vlan and the issue is gone, for a bit… After some idle time, 3-5 minutes, the issue starts over again. If we unplug the phone for 30 seconds, plug back in, the issue goes away for a week or more, ultimately the issue returns after a length of time.

When looking at LLDP neighbor detail on the switch, the ports where the issue is happening, LLDP remote device detail comes back with no device connected. Upon restarting the phone LLDP reports it correctly.

Before reboot:

LLDP Remote Device Detail

Local Interface: 0/20


Remote Identifier: 5629
Chassis ID Subtype: Local
Chassis ID: 
Port ID Subtype: MAC Address
Port ID: 
System Name:
System Description:
Port Description:
System Capabilities Supported:
System Capabilities Enabled:
Time to Live: 3474 seconds

After reboot:

LLDP Remote Device Detail

Local Interface: 0/20


Remote Identifier: 5730
Chassis ID Subtype: Network Address
Chassis ID: 10.X.X.X
Port ID Subtype: MAC Address
Port ID: 48:25:XX:XX:XX:XX
System Name: Poly Edge E220
System Description: Poly;Edge-Edge_E220;3111-86990-001,11;SIP/8.4.1.0068/23-Dec-25 02:11;UP/8.4.1.0068/23-Dec-25 02:11;
Port Description: 1
System Capabilities Supported: bridge, telephone
System Capabilities Enabled: bridge, telephone
Management Address:
    Type: IPv4
    Address: 10.X.X.X
Time to Live: 111 seconds

I have several Cisco CP 8851 on the network that do not have this issue at all, they follow the voice vlan tagging as configured.

I came across a post on another website with someone else experiencing the same issue:
https://community.zoom.com/phone-4/poly-edge-e550-maybe-others-problems-with-8-4-1-0068-firmware-79450