Hm... I'll try restarting them both then... the app restarted itself, but I haven't restarted the printer. As I mentioned I'd already chosen the upgrade kit camera option, so was expecting it to work... but maybe it needs a little persuasion!
Edit: Yup, that (manual restart of both printer and app) fixed it! Thanks @darkgrue
Oh, but the export image (when you click the camera icon in the top right corner of the image) is still rotated... unless that has been fixed in a later version of flux studio... I'm still on 0.7.4. It also looks like the camera view in flux studio doesn't show the full height of the image (when compared with the correctly rotated exported camera image).