[GenesisDH]

My suggestion for all with Nvidia Shield with Android 8.0

1.) first install original Netflix app and try if play 4k HDR
2.) if answer is yes, find ESN and manaul add to netflix addon ...

I hope this help... my Sony Android TV with Android 8  now can play 4k HDR ... this "trick" also work on my EON android box where before work only 540p resolution...this box have widevine L1 but not Netflix certicifate...

Android 8.0 works fine with the addon.
Android 9 (Shield Experience 8.0) does not work. When people say Shield 8.0, it’s possible they mean Android 9 which is known to have problems with 540p+ playback.

I'm on Kodi 18.4, Netflix 15.2, Nvidia Shield TV.
Everything works fine, no errors. So far, so good.

Please explain what Android version you are on.
It’s known that Android 8 (Shield Experience 7.x) works as expected, however Android 9 (Shield Experience 8.0) has issues almost across the board. So if you have Android 9, then maybe something can be figured out from your setup.