SUMMARY
When you open the Application Launcher and type with the keyboard to search for something, you expect the first item in the list to be highlighted, so that you can press enter to get what you searched for.
However, in specific conditions (see below), the highlighted item will be different even if you don't move the mouse: if the user has the habit of opening the app by pressing Enter, that will make them open an app they didn't intend to open.


STEPS TO REPRODUCE
1. Open the Application Launcher
2. Type with the keyboard to search for something
3. Hover the cursor to an item that isn't the first
4. Leaving the cursor on this position, press the hotkey to close the Application Launcher
5. Open the Application Launcher again, and type with the keyboard again

OBSERVED RESULT
What happens depends on where the cursor is right now:
- If you moved the cursor is out of the way, then the Nth item will be highlighted, with N depending on which item was highlighted when you closed the application launcher before.
- If the cursor is in the launcher, then it will highlight the item it's hovering, even if you didn't move it.

(It doesn't always happen, it's a bit inconsistent. It seems it happens more likely without any open application on the virtual desktop, and if the Application Launcher is opened (the first time) by clicking on it, instead of using a hotkey)

EXPECTED RESULT
If you don't move the cursor, the highlighted item is always the first on the list.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: NixOS Unstable
(available in About System)
KDE Plasma Version: 5.27.3
KDE Frameworks Version: 5.104.0
Qt Version: 5.15.8