Had the exact same issue I tried evetything ,I called support a couple of times,they sent me different versions but still nothing, I eventually gave up so I just took the Tv back to where I purchased it and they sent it back for repairs,afterall you get a four year warranty
Got the Hisense 50a6100uw about 2 weeks ago but when I tried to set up the wifi I was only able to connect to 2.4 ghz and not 5ghz ,along with the netflix issue of having to reset the app often i reached out to hisense support who sent me a link for firmware but I am not able to install it tried...