Jabber 12.9.1 CUCM 12.5.1 MRA 12.5.7 Internal call transfer not working

[UrbanPeasant]

Hi Folks, thanks for looking, here's the issue I've hit:

Windows CSF MRA Jabber userA calls external phone number, call connects, now needs to transfer the call to internal Windows CSF MRA Jabber userB, selects transfer, enters the internal DN of userB and dials the internal extension, userB answers, userA and userB consult, userA attempts to transfer the call and clicks the green transfer button - but nothing happens. UserA and userB remain connected.

If the external number calls userA, userA selects to transfer to userB, userB answers to consult, then userA attempts to complete the transfer, nothing happens; userA and userB remain connected until the call is terminated, whereupon userA can then resume with the external caller.

However, if the call is consult transferred to and external number, that works.

userA and userB are in the same Partition called 'internal.'
If the same thing is done as a blind transfer it works.

What am I missing? Why can I only transfer to an external number? I need to be able to do the internal transfer.

External consult transfer works, internal consult transfer doesn't.

Thanks
Nathan.

[UrbanPeasant]

I'm now pretty certain this is an MRA thing.
Further tests carried out:
Physical phone userA calls mobile, userA calls MRA CSF userB to consult transfer, consults, transfer completes successfully.
MRA CSF userB calls mobile, userB calls physical phone userA to consult transfer, consults, transfer completes successfully.

However, MRA CSF userB call mobile, userB calls MRA CSF userC to consult transfer, consults, unable to complete transfer, clicking the transfer button does nothing, need to end the call with userC, resume the call with the mobile, then end it.
It's as if the call is being carried out as a consult hold, instead of the consult transfer that it should be.
Blind transfer works fine.

I've now got logs for all the above and a traffic export off the CUBE to see if I can spot something. Perhaps there's a REFER not happening when the transfer button is clicked, so the actual transfer itself isn't occurring.

[Schwabby]

Did you ever get this resolved or find what ultimately fixed this issue?