We've also had the reset to Automatic every time we shut off and turn on the TV. It only started doing that recently and it's been a while since the last update. So not sure why it changed recently.
Automatic should provide the absolute best for each format. 4K HDR @ 60fps and if doing Dolby Vision cut frame rate back to 30fps. Just like the adjust frame rate to content setting adjusts frame rate.
Cutting everything back to 1080p on Automatic is annoying as it limits all content to no higher than 1080.
The new Roku Ultra does need an firmware upgrade. My new Ultra is setup the same as the old Ultra was. When I press Home on the Roku remote, it would turn on my A/V, TV with no problems. Now the new, when doing the same, the volume control won't work from the Roku remote. I have to power on the TV to let it power on the other devices for the volume control to work on the Roku remote.
On my 2016 LG OLED (E Series 65 inch), I have no problem with it staying set at 4K HDR10 by telling it to cancel auto when I set it up and "downgrading" manually from 1080P DV to 4K HDR10. The 4K HDR10 seems a bit better than the previous Roku Ultra, that I think was possibly outputting 4K with no real HDR.
But I have similarly complained about the lack of Dolby Vision at 30hz/30FPS. All the apps (Netflix, Disney, etc.) do actually support it, and on a RokuTV they work at 30hz. So this is a poor development decision on Roku's part. 2160P DV at 30hz is obviously way better than the **bleep** 1080p DV it wants to default to.
After years of waiting for Roku to support DV, I pre-ordered two of these at the $100 launch price, so this one remaining issue is a bit of a disappointment. Hopefully they'll decide to fix it, but at least they've been releasing updates to fix other issues steadily.
I have a XBR900F too and I, too, tried upgrading to pick up the DV support. However, I was forced to put the 4800R into the HDR mode because the default DV-enabled setting was seemingly attempting to run on non-native content, resulting in a horrible picture (blown out highlights, loss of contrast, muddy shadows and the look of standard definition). Either I got a lemon or I needed to adjust a setting (HDMI was already configured to use enhanced and 4.2.2 subsampling on the ROKU). In any event, once I went into the 4800R settings and pointed it to HDR the contrast, color and definition returned. It was unclear after putting the ROKU in HDR mode, however, whether or not native DV content would be shown without going into the ROKU settings and manually switching it back every time I anticipated that the content may be encoded with DV. Since you have the same model of TV, I thought I would ask: Does it sound like I got a lemon or was an TV configuration error to blame? (For example, I read a couple of pages back that the color space output from this model may be an issue, something I didn't think to tweak in the TV settings.)
You probably have a newer TV that supports dolby vision at 60 hz. Alot of the older dolby vision Tv's form 2016 and before only did Dolby vision at 30 hz and looks like Roku dropped support for 30 hz dolby vision.
Investigated a little more. I looked at my mom's 1080p with 4k hdr firestick. For display you have auto and then it lets you make all the manual selections you can make. 720p, 1080p, 4k@30hz, 4k@60hz, 4k hdr@30hz and 4k hdr@60hz. So these are true forced selections.
I then took my new ultra to my newer 4k tv's I use as computer monitors. When you pick auto it does auto select 4k DV. If I set it to 4k HDR, it scans and sets itself to 4k DV. So I consider this an "auto" setting vs a forced setting. Perhaps they try to minimize the selections. They should have an expert mode for forced settings or go back to how the old 4k HDR firestick works. A true forced settings would stay at 4K HDR and not try to revert to 1080p DV when their are handshake issues.
I also think this 4k HDR auto settings causes conflicts when there are handshake issues. Causing it to revert to 1080p DV which ROKU has deemed to be the default setting over 4k HDR or 4k. Bad choice on my opinion.
After seeing what this box does with a true DV 60hz TV and how the older 4k HDR roku stick works with a 1080P TV I then dived in to my ROKU ultra connected to my yamaha tsr700 (costcos version of the v6a).
If I connect the roku to my TV directly I don't have the issue with it reverting to 1080p DV when I have forced the setting to 4k HDR. So there doesn't seem to be a handshake issue.
I then played with the Roku connected to my yamaha tsr700/v6a receiver. This is a newer model that supports hdmi 2.1 and 120 hz. Moving connections around and playing with it I saw hdmi control jockying between my lg 4k player and the Roku. Some times I would get blank screens, yellow screens, pink screens or white snow over the whole screen. Sometimes the ROKU won't and was displayed and other times the bluray player did. I purchased newer 4k cables that support 48gbps that didn't help. I then spent the extras money for 4k 48gbps hdmi cables that were certified and that didn't help.
After further testing and disconnecting all devices from the yamaha receiver and just connecting the ROKU I determined the following. The roku doesn't like hdmi 1, 2 or 3 ports on my yamaha receiver. When connected to those ports the roku would revert to 1080p dolby alot when I powered off and back on. It happened most of the times but not always. Seems to be some handshake issues.
If I connect to hdmi port 4 or 5 (didn't try 6 or 7 since I had other things connected to those) I didn't have the issue. I will need to try and find out the difference between ports 1-3 and 4-7. What I do know is often on the back of a receiver they have a rectangle box around hdmi ports where they group certain ports together and other ports separately. This usually indicates differences between the ports. I can't find out what the difference is in the receivers set up program or the manual so I'll probably have to contact yamaha to find out the difference.
Based on this there does appear to be some type of handshake issues between the yamaha receiver, lg oled tv and the roku ultra. It could be 1 of the devices or several of them. Or just a handshake issue amongst them with newer devices (both the yamaha and roku are newer devices and may need patches). But based on this the reverting to 1080p DV may not be entirely Rokus fault. Minus the fact that shouldn't be a setting and it shouldn't take precedence over 4k HDR or 4K.
Update: Haven't found exact specs from yamaha but supposedly per forums ports 4-7 are hdmi 2.0b ports and ports 1-3 are hdmi 2.1 (with a note 2.1 support would come with firmware update/not sure if that occurred yet). So this may be a handshake issue with hdmi 2.1
For my 4800X and 2016 LG OLED, I leave it manually set at 4K/60 HDR - and it stays at that. Just don't ever set it on Auto for resolution, or it assumes 1080p DV is better than 4K HDR10. Dolby Vision 4K/60hz on my Sony X900F works fine, although it is a little washed out at times.
And to answer earlier question on the thread, it's not just specific apps. It's the entire Roku Ultra (and thus all apps) that doesn't currently support Dolby Vision 4K at 30hz, thus eliminating Dolby Vision as a viable Roku option for TV's such as us 2016 LG OLED owners (a lot of us hold onto these because they were expensive, the last OLED's to support 3D and still are wonderful TV's)