Sony a7iii 4k output select not available

[rjderama]

Hi all,

Calling in the "big guns here".  I've got a Atomos Ninja Assassin hooked up to my Sony a7iii.  I'd like to recored only to the external recorder to take advantage of Face Detection in 4k recording.  However, the option for "4k Output Selection" is not available (grayed out)

I've tried using another cable (even though the Assassin is showing it's getting a 4k UHD signal).  I can't seem to force the camera to disable recording only externally.  And, yes, the camera is set to MOVIE mode.....hmmmm.  I've also reset the camera to see fi this was some sort of settings problem on my end = no bueno.

 

Anyone think they can help?

Thanks in advance!

RJ