This isn't a Gamescope bug, this is a Steam bug.

Seeing the same kind of issue without HDR running Squirrel with a Gun.

Plasma Wayland on Arch Linux

gamescope -W 1920 -H 1080 -f -r 80 %command%

Experiencing the exact same issue on Fedora 41 Beta playing Ace Combat 7. However, it seems to be a game by game bug, as all my other games work fine.

I've been having this issue since at least November 2024 without HDR enabled in gamescope. Currently on Fedora 41 using Steam version 1733265492

I'm seeing this on fedora 41, with red dead redemption 2, steam version 1738026274.
gamescope -W 3840 -H 2160 -r 60 -f -e --hdr-enable --force-grab-cursor -- %command%

Same issue without HDR enabled in Dark Souls II: SOTFS. Plasma Wayland on Arch Linux using default Proton.

gamescope --adaptive-sync --steam -W 2560 -H 1440 -f -- %command%

Having this issue with Silent Hill f. I'm using scopebuddy to fix the Steam overlay, as I'm not able to use Steam Input or Overlay without it. I am not using HDR.

scopebuddy --force-grab-cursor -f -w 1920 -h 1080 -W 1920 -H 1920 -r 144 --display-index 1 --backend sdl -- gamemoderun %command%

Still unresolved as of 1759461205 and 1761786974 (beta),

I was directed here while discussing HDR screenshots in Gamescope, and I may have some info to help.
This image was captured by misinterpreting a 10bit swapchain (rgba1010102) as HDR image data, when the actual contents were only 8bit SDR

Very similar to the other images posted here, and most UE games seem to use a 10bit swapchain regardless if HDR is enabled or not.
So based on that, I think games are outputting SDR content to HDR swapchains, causing Steam to misinterpret 8bit values as 10bit and saving corrupt images as a result. Now the issue is how to find out if a game is actually outputting HDR...

@jonnyawsom3 that's very interesting (and a cool username 😎). Thanks for adding more info!

While it's not a permanent fix, would it be possible for Gamescope to somehow redirect the output to the SDR swapchain if --enable-hdr (or equivalent) is not specified?

And/or introduce a new --disable-hdr if it doesn't already exist, such that we can inform the system about games that don't support HDR (or we choose not to enable HDR) should not have its screenshot data treated as HDR content?

I say this not having a single solitary clue about how the internals of Steam/Gamescope works, but to me it would make sense for it to be exceptionally difficult for Steam to somehow detect whether the game is outputting HDR data. If that's a correct assumption, I think I speak for every poster in this thread when I say we'd be happy to add per-game launch arguments to control this if it means having working gamescope-enabled screenshots.

redirect the output to the SDR swapchain

The swapchain has bitdepth, which is usually RGBA 8888 for SDR and 1010102 for HDR, but it also has colorspace which is usually sRGB for SDR and a few options for HDR. I'd assume Steam/Gamescope is only checking bitdepth, but games do exist which output 10bit SDR or have 8bit stored in 10bit swapchains which makes it a lot more complicated and causes the corrupted images.

Getting even more technical, it looks like Vulkan has VkColorSpaceKHR to list the current colorspace, so checks can be performed against it. For example, ReShade already does this. Checking the colorspace here and then using that to select SDR or HDR here.

I'm also experiencing this issue. Is there any way this could get prioritized ?

Dropping in from Googling and Reddit. Also having this issue. From 2024 huh, I don't see this getting fixed anytime soon.

I'm also having this issue with "LEGO Batman: Legacy of the Dark Knight" using this flags:

gamescope -W 2560 -H 1440 -f -- %command%

2026, same problem as OP, on bazzite, using Scopy Buddy.

Just noticed this issue in Ready or Not and MECCHA CHAMELEON, both running with Gamescope, both do NOT have HDR enabled as they do not support it. Game looks completely fine.

Launch command: gamescope -b -H 1440 -r 360 --force-grab-cursor --mangoapp -- gamemoderun %command%
Running Artix Linux, 7.1.3-zen1-1-zen, KDE Plasma 6.7.2. Using Proton Experimental.

seeing this issue too on Voices Of The Void (non-steam game added to steam) but NO HDR is enabled, just running through gamescope. The game looks normal

gamescope -W 3840 -H 2160 -b -- %command%

Wow best looking one yet! :)

I still don't understand why this is still a problem. The issue is more than 2 years old and very detrimental to all linux users. Needing to rely on 3rd party software for screenshots and not being able to make some inside of steam, which are the only ones you can publish also, is very tedious and annoying..