Opus and Dorico - playing back but not exporting and not too keen on external SSD's - Am I alone?

I’m pretty much 100% convinced that this is an Opus issue and not Dorico - but I want to not assume, and also to ask if this is specific to my set up - so…

I have a simple English Horn patch in Opus that plays back just lovely with Dorico. It is one of the new Opus specific patches. Yet this part (and this part only) is missing when I export the mix as a whole (a single uncompressed wav for the flow.) I replace Opus with a different VST and the part exports perfectly.

Unrelated (or not) I have the samples for Hollywood woodwinds on an external SSD. Opus and the new EW Installation Manage both seem to loose track of those samples on occasion. But re-linking them has no effect on exporting. I know I didn’t give enough info to diagnose and don’t want to waste anyone’s time. Mostly wanted to ask, Is it just me?