I'm having an issue where as soon as I add any image source (local or internet source) to a profile the wallpaper profile window becomes very slow. I've selected "Use a different image for each monitor" and did slidehow and single image with similar results, albeit much slower with slideshow for local images. Using a single image for all monitors also slows the UI, but not as severely. For example if I add "Astronomy Picture of the Day" source to a monitor switching to other monitors in the wallpaper window takes 2-3 seconds. If I add a local source slidehow from a library that switching takes 5 seconds. If I change it back to "Solid Color" interacting with the UI becomes instantaneous. This isn't applying the wallpaper or loading the image it's just interacting with the wallpaper window itself. I've tried searching and I'm not finding anything that isn't about actually applying the wallpaper so I'd be very appreciative of any help to try to track down the issue.

I did a bit more testing on this. It appears like it might be related to the size of the image. Larger images cause a bigger delay than smaller ones. I guess if there's some kind of scaling going on in the preview section it might take longer to downscale the larger images and lag the UI while it's doing that? Troubleshooting info attached, but I'm less convinced now that this is a real bug and thinking it might just be down to trying to show really big images in really little boxes.