No Skype voicemail when using Skype Gateway?

[mobidutch]

I have my Skype account configured to go to Skype voicemail if I don't pick up a call within 30 seconds. In 3CX I route my inbound Skype calls to extension 10, and for that extension I have specified that calls should ring for 60 seconds before the no answer rule applies. But in incoming call never seems to go to Skype voicemail...keeps ringing for 60 seconds and then goes to my 3CX voicemail. How can I make it use Skype voicemail instead?