STEPS TO REPRODUCE: 1. Right-click on desktop > Configure desktop 2. Click on the combobox that says "Image" and try to switch to another wallpaper plugin EXPECTED RESULTS The plugin is changed. ACTUAL RESULTS The plugin is not changed, the combobox does not update, the Apply button on the bottom of the page does not become active, etc. This is in the 5.15 branch. Sadly nothing informative is printed to the console. Note: changing wallpaper plugins works just fine from the lock screen and SDDM KCMs. It only fails as described above when used on the Desktop Containment window.
Is that the only combobox broken? There's been some serious issues in QQC2 combobox recently.
Ah, I see now that all the comboboxes are broken. :/ Seems like fallout from the recent qqc2-desktop-style changes.
Looks like Marco just fixed this a little bit ago in https://cgit.kde.org/qqc2-desktop-style.git/commit/?id=581b140c8b81096f40ddebd84b8b2fbc327b616d. Works for me now.