I got my nvidia shield tv two days ago and I have the same issue. Updated to the new android nougat that came out today too and it's still the same. A lot of people seem to have this issue with Netflix on the shield tv. Not only with B&O but Samsung, Yamaha etc. Nvidia seems to ignore questions about it and Netflix is impossible to reach except by phone - someone was recommended to switch from wifi to Ethernet... like why? Would probably not make any difference.
I think there is either a bug or hardware issue - but probably the first since the issue is still there in the new 2017 edition (just smaller and without IR and micro USB/micro sd card slot.
Also, on a side note I've been experimenting with resolutions. I have an Apple TV 4 and it's set to 1080P@60hz which is very smooth on the Avant.
It seems that the scaler in Avant (from 1080P to 4K) is much better than the Nvidia Shields own scaler is. I watch a lot of old shows (frasier mostly) in 576i/p that is scaled good on the Apple TV via the Avant upscaler to the panel resolution. On the Nvidia it looks much worse. If I set it to 1080p it goes better but I still believe the Apple TV looks slightly better.
Also noticed that I don't get he natural motion flow hat B&O uses in its video engine if I use 4K@60hz. It works on Apple TV at 1080P@60hz so I'm surprised it seems to be lacking on 4K@60hz. It does however work on 4K@30hz and it makes the motion very fluid and more lifelike. I very much prefer that. I wonder why it seems to be of at 60hz. The shield is not very good at pushing lower frequency video over a 60 frames signal. It stutters a bit and looks less lifelike, especially on panning video. Keeping it at 4K@30hz gives me more fluid video but also less fluid GUI since it's designed for 60fps and therefore loses some frames. I still haven't found a good solution here. I am not quite sure how it works on the 1080P source, if Apple is also doing some smart frame interpolation like B&O does from 23/23/30 to 60 or if the B&O video engine just doesn't work well with 4K@60hz mode. It looks very much more tiresome. I'll continue to investigate over the upcoming days.
But, the Netflix issue is annoying. Netflix uses Dolby digital plus. It works on Apple TV 3 and 4 for me so it should definitely work on the much more expensive and advanced Nvidia Shield TV too. Especially since it's marketed as the best streamer available..