Hi there thank you for that information, I have commented on some of your findings.
- When I park a call, I cannot retrieve it. There is no visual indicator.
This is valid, we will check the front end for this item.
- There is no audio and microphone on both applications.
Are you on a secure connection, for example https://yourdnspbx.com Once login securely the PBX will ask the user permission to use the microphone as well to allowed notification by way google chrome.
If you don't have certificate please review this video on how to setup your lets encrypt certificate.
- The buttons for hanging up or putting the call on hold in the top right corner are not working.
You are correct once you put the call on hold, right hand panel call box hold button is non-responsive
same for incoming call same behavior.
- I cannot add a new phone from Accounts/extension/provisioning menu. I have to go to Device Management in the advanced settings.
The Device management is the new location for provisioning the phones going forward.
- the yealink_commun.txt is coded to german
The original file is English, Could you send us a the .txt file on this ticket?
Also is your desktop phone using the German IVR language and Web?