So AFTER I bought their HEVC codec it now tells me "It looks like you don’t have any applicable device(s) linked to your Microsoft account. To install, sign in on a device with your Microsoft account."
Whats wrong with this? The 1080 Ti is supported.
Edit: Rather than just deleting this post i'll update it in case it can help anyone else. While it wouldnt install from the browser, when i signed in through the microsoft store app within windows 10 it then installed. And yes now its working in playavr (and wow, decoding takes 50-60% of my 1080 ti).
Thanks for your help.