PT10 not seeing 2nd interface (digi192)

I'm running PT10.3.10 HD Native with an Avid 16x16 Analog interface. I just bought an old 192 with 2 analog output cards and connected it to the expansion port of the 16x16 interface to increase my output total to 32. When i run Digitest, the 192 is being detected. But it's NOT showing up in the Hardware Select in Pro Tools. I've tried trashing prefs, moving the 192 to the 2nd port of the soundcard... no luck. Anyone with a similar situation? Fixes? All firmware is updated, LOOP Master light illuminated on the 16x16, LOOP light illuminated on the 192... a mystery.