If setting 'transfer on hangup' is set to on and the first call was picked up with a PBX starcode then the transfer will be done if this setting is set to on. Info: a picked up call with starcode is an outgoing call. But an incoming and an outgoing call is the condition for the 'transfer on hangup'.
Setup - Advanced - Behavior (Tab) - Keys (Section) - Transfer picked up calls

N/A
| Parameter | Valid value |
|---|---|
| <transfer_on_hangup_with_starcode perm="PERMISSIONFLAGS">VALIDVALUE</transfer_on_hangup_with_starcode> |
|