EPM, S700 and SIP Secret

Hello,

I just deployed a new S700 with EXP100 on Freepbx 13.0.192.16 with Asterisk 13.14.0

Used Zero Point config IP/URL redirection to TFTP on my server and this seemed to work fine. The S700 configures with my name, extension, BLF keys however registration fails. If I login to the phone through my browser all I need to do is paste in the correct SIP Secret and the phone registers.

Firmware appears correct, EPM template has Firmware Slot 1 loaded 1.37 (2.0.4.33) and the phone lists IMG–2.0.4.33(2017-07-13 21:46:00) so this looks good.

I have GUI Override set to Config File, so EPM should have preference. Right?

Thank you for any help,