We are having 15.5.7262.2 PBX on test and having problem with 183 Media Change. When this event happens time to first ring on destination takes approx 40 seconds. I have traced down that this happens when the called number from MakeCall (3cxpscomcpp2.dll) or when is used as destination number in CallFlow. In cases when number is being called from HW phone (Yealink) or SoftPhone the time to first ring is normal - like 6 seconds or less. Also when number is used in Forwarding rules on Away status (Forward to Mobile) everything is ok. Im attaching one of example dumps for better representation of problematic issue.