I was excited to see the UHD app support for the 2018 Sony TVs out of the box, and pre-bought a couple of UHD flicks on Vudu while my new set was shipping specifically because of it. Unfortunately, on my 900F the app is broken. It does not engage the local dimming technology (regardless of which quality is selected) and as a result even the UHD picture is much inferior to the standard HD picture available through other apps (thank goodness for movies anywhere). The way a blank black screen looks during a menu when no local dimming is activated -- i.e., the screen is not a deep black and uniformity issues are visible -- is the way the screen looks for the entire movie in Vudu. Also as a result, colors are dim and bland. Is this a known issue?

Update: At some point in the process of troubleshooting this with Vudu support the problem cleared. The app is now working correctly on my TV and the the picture looks as it should across formats. I have also confirmed I am receiving 4k/HDR. I don't know what fixed it...we were going through the boilerplate reboot/reinstall steps I was skeptical would make any difference and one of them must have done the trick. Mea culpa.