Dear All, I just discovered interesting behavior (bug?). I have 3CX V15 PRO and successfully configured TLS. Clients can register on 3CX over TCP/TLS and establish a session. However, as soon the call is put on hold - after you return back there is no voice in both directions anymore. I tried with hardware and software phones, both internally and over the internet. Do you have ideas what I could to to investigate or this is known bug?