DTMF Type issue

Hi,

PBX: Yeastar Cloud PBX version 81.8.0.112

T23G Yealink Phone

Situation:

A client has a helpdesk system with a phone number linked to his helpdesk account. When somebody dials this number, you'll be asked to press some numbers (key press event). The client dials this number from his T23G Yealink phone but unable to press the keys. There was no tone whatsoever and the call couldn't get through. So what we did was to change the DTMF type on his T23G phone from RFC2833 to inband. After that, the issue was solved.

However, when the client wants to access his voicemail and input the password, the response was "login incorrect". There was no tone coming out from the phone but when DTMF type RFC2833 is used he could hear the tone and managed to listen to his voicemail but can't call his helpdesk phone number.

On the PBX advanced tab, his extension's DTMF mode is RFC4733 and when set to AUTO or INBAND, the problem still persists.

If only on the Yealink phone, I can change the DTMF type to AUTO where it would adjust itself to RFC2833 and Inband but AUTO is not on the option.

Have you encountered a similar situation?

Your help would be greatly appreciated.

Thanks.