SUMMARY The Wallpaper KCM and the Appearance page of the Screen Locking KCM in KDE System Settings use grids of different sizes to display wallpapers creating an inconsistent appearance when browsing wallpapers in different sections.
Can confirm. Looks like the delegate size shown in the Wallpaper KCM is inconsistent with the desktop version of the wallpaper chooser as well as the Screen Locking KCM.
Can you provide a screenshot highlighting the issue. I couldn’t find it. The issue might be due the wrong display being selected by default.
Huh, it's fixed for me now as well.