I know well the standole Dolphin but not so much the Retroarch core yet, from my experience, you can’t expect every game to run without problems with it right now, I tried F-Zero GX for example, and there’s a weird glitch that prevents cars / roads to appear. Basically, you just see a bunch of buildings and city backgrounds but nothing else, you can boot, go through menus, start without problems, but you won’t be able to do or see anything in a race, it’s just void. Problem has been reported by other users too.
Perhaps Star Fox suffers from a similar problem where the Retroarch core is unable to run the game properly for now, I can’t verify right now to tell you on my side but I wouldn’t bother too much if you don’t get more specific answers.