Also can't calibrate the HDR or Dolby Vision color space because it doesn't differentiate them with the SDR color space in the expert settings. Being able to calibrate HDR color space is an advertised feature in the product manual.
Please give this issue the attention it deserves, it will be beneficial to your company in the long run.
BuggyChoo is correct. I have been complaining about this forever. I keep getting emails about my ticket saying they need more information which is rediculous. They have no intention of fixing this issue and YES it's a real issue. I am surpirsed that not more people are complaining about this. It seems like I am the only one who has brought this up. I have contacted TCL and Roku and it's like they don't care. The app is broken. I even emailed to the developers email on the Play Store and Nothing. We need to keep complaining about this to get them to finally listen. Fix your app Roku.
You can download an older version of the app until it's fixed or if ever fixed and it will display the HDR modes. Select any version from 4.2 or lower. 5.0 or above won't have the HDR mode.
Before you download the old version. You have to delete the new version from your phone. Also ty have to turn off auto update on the Play Store so the Roku app won't automatically update to the new version..