Cannot leave three-way on internal transfer

[ClearCall]

Most of the time transfers work as expected, but when we transfer to an internal SoftPhone extension, we can't leave 3-way, hangup transfer line or hangup.
Blind transfers work. Transferring to a logged-in agent from the drop down list works. Transferring to an external telephone number works. The issue only occurs when transferring to an agent's extension directly to the SIP phone.

This is an issue in my production environment as well as my test environment that has the latest ViciDial version. I have seen many fixes related to 3-way when doing SVN upgrades, but none have resolved this issue.

[mflorell]

You might have to send the call through an IAX loopback trunk, because VICIdial is looking for an Answer signal, and that might not happen if the call is transferred to an extension on the same system as a final destination.