I have had this problem for months and it is NOT a simple permissions issue! As someone has shown earlier, there is no existing permission set for Netflix on my computer ( ad3e2fcc6a9ab87b8ce6dd83986dcb4e.png
). I have tried uninstalling and reinstalling everything that could possibly be related. Netflix will not ask to stay fullscreen on Chrome, IE, or Firefox. Every other website with a Silverlight player WILL ask to stay fullscreen. It is something on Netflix's end, that's the only possibility I can think of. Conveniently, Netflix has no way to report this issue to them.
Kind of a workaround I have recently figured out, is to F11 fullscreen the browser and CTRL+minus to zoom way out of the page so the Netflix controls become tiny while the video takes up the gained space. Practically fullscreen.
It's unfortunate that this isn't a more common problem, I'm doubting it will ever be fixed at this point....I've been dealing with this on my new laptop since around August. Old laptop had no issues with Netflix.