Analog Heat mk1, Studio One- No Audio over USB

Hi Everyone, I may be missing something obvious. Ive got an Apollo 8 and I can use the AH perfectly as an analog device and overbridge works in that situation.

Ive been trying to use USB for the audio as opposed to the analogue ins and outs, as Ive read that is possible and gets past any need to route actual cables. So far Im not able to get any audio over USB,
Ill have an audio track, put in AH as in insert plugin but all i hear is the track in its normal state…the controls are still synced but I cant seem to get any audio into it. Am I missing something here?

Many Thanks