Transfer issue

Have some soft phones (but not all of them) that can start an attended transfer, connect to the party being transferred to then hang-up but the call being transferred never gets handed off to the new party and, from the person being transfered perspective, stays “on hold”. Features appear to be properly loaded and other phones on the same PBX (hard and soft) work just fine. Nothing sticking out in the CLI or log to date. Still testing variable combinations trying to find a pattern.

Please provide the protocol debugging trace output for the channel technology used by the phones.