Here's a screenshot from my desktop (Gentoo; Plasma 5.24.5)

Any idea why "Help" shows up twice? I tried to "hide" one of the instances, but that won't work. I usually use the application menu illustrated above. The application launcher has the same problem. "Application dashboard" doesn't show "Help" (or KHelpCenter) at all. I tried digging around in my ~/.config directory, but no luck yet. Very strange. Any idea how to fix it? Thanks!

I figured it out! Somehow or other I managed to install an "org.kde.khelpcenter.desktop" file in /usr/share/applications/. If I just delete that file, I'm back to a single "Help" entry in the menu. Not quite sure how that happened, but at least it's fixed.