When you open the application launcher, if your mouse happens to hover over another category then the listed icons change to that category.

99% of the time I am launching things from my favorites section, but sometimes when I open the application launcher I accidentally hover over a category, so I have to switch back to favorites or just double tap the super key to close and reopen the menu.

I used to use a widget called Simple Menu: https://store.kde.org/p/1169537/

It had an option that disabled category switch on hover, you had to actually click on a category in order to change the category. I loved this, it was perfect!

I stopped using simple menu for a few reasons:
1. anytime I installed a new application, the favorites menu would become empty until I clicked into a category then back to favorites.
2. it was not resizeable. (application launcher is if you hold down the super key then use the right mouse button to drag)
3. application launcher now has a favorites section that looks so similar to the simple menu.