[Southsidemusic]

I would try resetring the HDX card into a different pcie slot as that did the trick for us before getting our trashcan Mac Pros so maybe try that first.

After switching slot do a PRAM reset and see if that works.

I would also make sure that the HD driver is uninstalled correctly with the uninstaller innthe HD Driver folder and restart computer and then run the HD Driver installer found in your Avid account.

And if prompted after moving the card and reinstalling the HD driver to do the firmware update press OK or Yes on that window.