@rwize @Databarinc It appears likely that this issue is related to and is discussed in (and indeed may be resolved by) recent comments from another FreePBX issue which I opened some weeks back:
I believe it would be helpful to quote the comments by @rwise:
For those without EPM one has to export your certs and then import them to the phones. If you are not using the End Point Manager module, then this means a manual process, I can verify it works as we updated one of ‘shared’ pbx’s and encountered a phone disconnect issue even after updating the phones vpn certificates until we updated the Sys Admin module. The Sys Admin module has to be V.15.0.21.17 or greater.
Here is the command to run from the console and root access:
“fwconsole ma downloadinstall sysadmin --edge”
For others who have not “rebuild” their certificates, I recommend not to until you are ready to update each phone however you do that in your environments.
Here is a link again to the bug case I opened and obtained the guidance from FreePBX support:
[FREEPBX-22242] OpenVPN breaks after Critical Update - Sangoma Issue Tracker