El Capitan Compatibility

Hi All,

I am attempting to use:
Wavelab 8.5 with
El Capitan, Macbook Pro Retina and an Apogee Ensemble Thunderbolt 2.

I am experiencing a problem getting my Wavelab to monitor through the Apogee interface. It chooses to playback through my internal speakers on the Macbook. It seems that it may not be compatible with the Thunderbolt 2 connection. Has anyone any clarity on this issue.