Transparency?

[dr460nf1r3]

Looks indeed broken haha. Just a guess, what’s your kwin-effects-forceblur version (if its installed)?

Edit: aah, this basically:

Application Launcher transparency settings?

The setting might be Better Blur. On some installs it got disabled after Plasma 6.4. Just reinstall the bumped version sudo pacman -S kwin-effects-forceblur But Better Blur, as well as the default BLUR from KDE, affects all windows, not just the Application Launcher. Make sure you rebooted after your Plasma 6.4 update.