Comedian mail DTMF Signalling and Cisco 8941

i have FPBX 14 + Asterisk 13 (built with the patch for call manager) and i am trying to get the DTMF Signalling working on Comedian mail, when calling out to any IVR though my IAX2 trunk to - or via my PSTN line - i can use the RFC2833 DTMF Signalling without any issue - but when i call the Comedian Mail - i cannot use the buttons to manage it - so no listening to voicemails / managing the Comedian using the handset. (I had this issue before applying the call manager patch).

Not so much of an issue as it does email me the messages, and i can get them via the UCP, but it would be nice to have it working. The handset seems to be working normally overall and can make and receive both video and voice calls.

I have now sorted this out by upgrading to a newer firmware - NOT - the 9.4.x but the newest of the 9.3.x SIP8941_8945.9-3-4-17 - the 9.4 would crash and the phone would restart. All working nicely now the CP-8941 is a great cheap handset AFAIK - seem to be lots around due to EOL i guess.