Any takers please? I've run all the latest updates including camera raw and it's still not showing. According to the Apple website my camera (Sony A9ii) is supported. I've also recently downloaded some sample images from the Canon G5x Mark II and they don't show any thumbnails either. Strangely they do show from my old Nikon cameras (Z7, D850 and D750).
I'd really like to figure this out as it's quite frustrating.