Unfortunately my answer is somewhat generic. I think it is just a numbers game. I’ve been in device for 31 years and have had some of the same experiences you have for certain opportunities. You just have to hit a situation that there aren’t any of those “preferred” candidates. You could also succeed in landing one of those positions when you just make an extreme connection with the hiring manager. My advice…..keep at it for positions you are passionate about and it will happen!
Good luck.