You might consider that a bug, but I call it a feature. I have no idea why Roku even added that setting in the first place, because HDR always on changes the video image, and not in a good way for SDR content. I realize that some people prefer "brighter" images, but it's not accurate and with some content looks really terrible. I only know of one other player that has such an option (Onn 4K Media Player), and it looks just as bad on that one as it does on a Roku.
As a reminder: HDR Always On did not create actual HDR images. It only alters the color mapping and brightness of the display. True HDR/Dolby Vision provides a accurate and vibrant image, but that's because the image is mastered to show it correctly in that mode. Any artificial HDR creation by a player or display is never going to be accurate.
I'm not posting this message to discuss the need (or lack thereof) for it, I'm reporting it as a bug in V12.
As I said, the slider used to work in the intended way and as of V12, it no longer does.
I used to be able to tell it to stay on all the time and the feature worked. Now, even though the slider says it's on all the time, it isn't - unless I do the workaround of turning it from On to Off and back to On.
I'm not sure what TV you have, or what your picture settings are, but Dolby Vision always on looks absolutely stellar on my OLED LG C1. That's the reason I turned it to always on to begin with - I got tired of leaving it off and messing with the picture settings every time I switched apps. It isn't simply a brighter image. Youtube, YoutubeTV, and all other SDR content is dramatically improved with DV set to always on.
If you're satisfied with the end result, that's all that matters in the end. I agree that the switch should retain its setting, so that would absolutely be a flaw/bug.
I don't have an OLED set, so can't speak to how it might look different than mine. As I said, your satisfaction is all that matters. My personal experience with HDR always on was it was unnatural looking, and that was with both a Roku and an Onn player, so two different devices with the same result.
My issue is the reverse of yours. I cannot get my Roku Ultra to remember my display or HDR off settings from one session to the next. I have the settings set to HDR always off and display auto detection off, but at every start up the display goes to "automatic detection" and puts the HDR on. I am using an LG UST projector and HDR is TOO dark, especially with Disney+.
