one way audio on T23G from external call

[obeyealink]

Hello,
I have a problem with the phone Yealink t-23G with firmware 44.80.0.70 and a telephone switchboard draytek vigor ippbx2820 with the latest firmware.
When you receive a call from the outside you do not hear the sound, while the caller hears.
If it makes a call to the outside or between internal phone audio is heard.
You do not hear the audio in the handset it with the hands.
I tried with all types of audio codecs, but nothing changes.

I noticed that on incoming calls if I press the hold the line falls, while this does not happen on outgoing calls.

With T-22 or cordless phones W52P there are no problems.
I am attaching documentation, what can I do?
Best regards,
Oberdan Albertoni