Your attached debugs don't show the SDP details which makes it hard to see exactly where the failure is happening. You might try setting voice transfer-mode network and/or voice forward-mode network.
Configuring the PBX to record the call sets it up as a conference call with the PBX recording function being one leg of the conference.
Be careful. Allowing a PBX to set up outside-to-outside forwarding is a vector for toll fraud. Make sure your PBX is well locked down in terms of web and DTMF passwords, also international calling.
