UCP issue, Media URL could not be loaded., cannot playback message, listen at phone will not function

When users log into UCP and attempt to play a voicemail message, Media URL could not be loaded. is displayed. Also, listen at phone is also non functional. Users are able to download and listen to voicemail. Presence state works and can be changed.

UCP is accessed at http://(my_actual_hostname_is_withheld)/ucp/

WebRTC is enabled in modules and user management. Certificate management has a cert installed.

Users are still able to access voicemail correctly from http://(my_actual_hostname_is_withheld)/recordings/index.php, the old user portal. They are able to listen from the browser, listen on phone, download, delete, etc. All functions work.

running 6.12.65-31, FreePBX

You should upgrade to version 13. We are no longer fixing html5 audio issues in 12