Polycom 335 cannot perform consultative transfer

Info:
Freepbx 2.10.1.3
Asterisk 1.8.15.0
End Point Manager (phones updated bootrom and configs, no changes to original config xml)
Polycom 335
freepbx is on a public
All phones are behind nat at home offices (nat is enabled for all extension that apply)

Issue: Cannot perform any type of consultative transfer. Blind transfers to queues as well as outside numbers works perfectly. All other tested functions work as expected, on hold, blind xfer, etc.

Logs:

As soon as the transfer button is pressed a second time, MoH stops and the hangup macro is called.

-- Called SIP/fpbx-1-7c3ce44a/1713909xxxx
-- SIP/fpbx-1-7c3ce44a-00001e1b is making progress passing it to SIP/4010-00001e1a
-- SIP/fpbx-1-7c3ce44a-00001e1b answered SIP/4010-00001e1a
-- Stopped music on hold on SIP/2010-00001e19
-- Executing [[email protected]:1] Macro("SIP/4010-00001e18", "hangupcall") in new stack

Things I’ve tried:
*2 transfer (doesn’t work, hear the ‘transfer’ message, when ** to disconnect, hangup for all parties) (verified that feature codes match)

Any suggestions?

Edit:
I’m thinking this is * related, from a SPA942, transfer also fails.