I don't know when the update occurred, but things work differently now since the posting of this thread.
-Go to: Settings > Display type
Display type menu
-Manually select an HDR option. Roku will then perform a hardware check. (In my case, hardware check fails with 4K HDR 60Hz, but succeeds with 4K HDR 30Hz)
-Confirm settings when prompted.
-Now here is where things are different! Roku now pushes this notification after manually selecting 4K HDR 30Hz
-Test. Checking with the same movie as originally shown in post
TV: Samsung UN58MU6100
Roku Ultra displays 4K without any issue on every app except Disney Plus. I understand Disney Plus is supposed to "auto detect" max specs, but it does not detect 4K on my Roku Ultra.
In my Roku display settings, instead of having auto display per input source, I have tried the Disney Plus app while having both 4K 60Hz and 4k HDR 30Hz set on Roku (apparently my setup isn't capable of 4K HDR 60 Hz) and no matter what, movies default to HD, not 4k.
Disney+ on Roku Ultra
I decided to try some diagnostics and I opened Disney Plus app on my TV to see what specs I am provided with the exact same hardware, exact same movie. Here is the result.
Disney+ on Samsung TV app
Therefore, the problem lies in communication between Disney Plus and Roku Ultra. Disney Plus cannot detect the specs of my setup through Roku Ultra properly.
I have read on other forums that if you force 4K HDR 60Hz on Roku Ultra, the Disney plus app then displays 4K resolution in app, but since I apparently do not have that capability with my hardware (when I force 4K HDR 60Hz I lose video feed on my TV), I fear that I am out of luck. This wouldn't be an issue if Disney provided users with audio and video settings outside of what the app "auto detects". Regardless, does anyone have any solutions aside from Roku and Disney getting their act together?
Going from 4K hdr to just 4K in Roku settings seems to turn off the ability to watch Disney plus in 4K entirely because the 4K icon disappears from description pages. Is this supposed to happen? I don’t like the way hdr makes everything dim and bland but I still want to make use of my 4K device.
Same boat as you. Can watch Netflix in 4K through my roku ultra but can’t watch disney+ in 4K because the Disney+ app isn’t recognizing my non-hdr 4K tv. Roku folks said to contact Disney+. I have done that but they do not truly understand the problem and just give stock answers that don’t address the real problem.
how are you able to force 4K 30Hz on the roku? I am able to do something similar with my Nvidia Shield and i am able to get 4k HDR out of the Disney+ app but on the Roku Disney+ app i am not able to get HDR only SDR. My setup is involving a projector though (epson5040) via a Denon AVR. Sorry if this is different but was curious.
Reply to JOjr: Your question prompted me to discover the solution to my problem! I have updated my original post with the solution, and there you'll find the answer to your question on forcing HDR. It's in the Display type menu.