This is happening every alternate time or so and eventually I have to restart the tv to return Netflix back to normal state where it shows DV and 5.1 logos on the supported titles like Our Planet, Stranger Things. Otherwise it shows only HD on literally all titles and plays in shit quality too. I haven't messed with any settings but just you should know I have VU Premium Android (55-OA) which is not optimized for Netflix as it comes with an error code (-14) (but fyi this TV supports Netflix, if not natively, to the fullest as the R&D guys tweaked some shit and got it working and I haven't experienced any problems other than the one I have made this post about) on every app start.
My TV also does this at times, mainly if I switch from my Amazon fire stick to the Netflix app. I believe the Dolby Vision/Audio from both devices/apps seem to conflict with each other. It is actually quite odd and annoying at times.