Having the same issues on my Hisense Roku TV since software update.
Roku TV 7215X
Hisense model 55R6+
Serial number YNOOAG156713
software version 10.5.0 build 4201-39
Tried every suggestion I can find, nothing helps. Any way to uninstall update? Can I use another Roku streaming device on a Roku tv? Am I sol?