I have had nothing but issues with netflix playing on my mibox. I tried swapping cables, and between tv's but I could never get it to play. I even factory reset the device about 6 times with no luck. I hated fighting it.
The wife and I ran out to the store to buy a new sectional, when we came home and set it up the TV was too small :) So we went to BB to look at TV's.
I settled on the LG 60UH6035 4K and it is a great picture!
The only app the TV itself won't do is PS VUE so I dusted off the Mi box to watch some Sunday night TV and to my surprise Netflix works, everything works on the mibox on this TV, with the same HDMI cable is before, and sound hooked up the same way, HDMI to TV, Optical from TV to soundbar.
My older TV's were both Insignia, a 49 inch Plasma 720P and a 50 inch 1080P set from black friday a few years ago.
All i can say is this television has completely changed my opinion of this device.
HDCP can be a harsh mistress.