For those who are having problem with SD Netflix; yes, uninstall-off/on-reinstall method works till next update of netflix then it will be switched back to SD. I don't know why it is not explained here since Samsung Store has a different release of Netflix than Google Play Store and this version recognizes widewine level of your device. Permanent solution is uninstalling Google Play version of Netflix and installing it from Samsung Store(and continue to update it from Samsung Store). Before I was using the method explained here and it was always switching back to SD after some time but it passed now more than 6 months since I deleted Google version and using Samsung Store version and it is always FHD for me.
