I had exactly the same issue as you, with a gtx 980 and windows 10, and after hours and hours of trying, I finally figured out what the problem was for me. Apparently geforce cut support for miracast a while ago, as microsoft took over or some shit, idk. Well anyway, I rolled my drivers far back, as far as 350.12 https://www.geforce.com/drivers/results/83819
After I did, I panicked a bit, as my screen went black. I hit ctrl + alt + delete and restarted my computer from there. It booted up with image and on 350.12, and after that, i could connect to my tv without any issues