Forward on Response Group to PSTN telephone number not working 2

Forward on Response Group to PSTN telephone number not working
I came across an issue regarding the forward on a Lync response group. There was a queue time-out enabled and set to “Forward to telephone number”. This field was filled with sip:+31301234567@domain.com (where domain.com was the SIP domain).  When a call came and hit the time-out, the call was forwarded to the number specified, but ...