I’m not doing any fancy coding, just imported six images, made cubemap, and dragged them into my skybox.
However, as you can see in the attached image and linked project, the resulting skybox is blown out, almost entirely white, in both the upper-right review window and in the scene itself. This happens with these images (JPG), as well as others (PNG) I have tried. I have deleted and recreated the Prefiltered Data a few times, but that seems to make no difference.
I searched the forums, and it looks like people had a similar issue with HDR photos back in 2018, but that issue was marked as a bug and resolved, and these aren’t HDR photos, just images generated in Photoshop. So this may be a different issue?