[ThosSounds]

Hi Dave and thanks.

Been talking to Sonnet's tech team who are fantastic. They sent a list of things to try including those you mentioned. Initially the Mac was seeing the chassis and two UA cards in it, but not the HDX card at all. After resetting the PRAM and uninstalling/reinstalling the HD driver the Mac can see the HDX card and I have this issue where Pro Tools doesn't see any audio interfaces attached.

I've tried the HDX card in two different slots in the Sonnet chassis, though they say it should be fine in any of them. I did look at my iLok and yes, it's showing the licenses for Ultimate and digilink.

My old system was a 2010 Mac Pro and the card and interfaces were working fine running OS 10.13 (with the cards internal). So.. seems like it must be somewhere along the lines of newer OS, newer Pro Tools version, chassis?

Thanks!