KDE

What distro?

You really shouldn't have 6.0 unless you're on a rolling distro that's very fast at updating packages. Even Arch doesn't have 6.0 in the main repos yet, you only get it if you enable the testing repos. And that's kind of what you sign up for with rolling distros, especially with testing repos enabled.

@Fleppensteijn @Max_P The change in the first component of the version number from 5 to 6 is what could have tipped you off. I mean, admittedly there's no universal standard for software versioning that everyone follows, but the closest thing there is to a commonly adopted standard (https://semver.org/) says that when the first component of the version number changes, it's a big deal and things might break. (Or, a relatively big deal, but just how big that is in practice depends on the package.) If you didn't know to look out for that, now you do. 😀

Unless by "average user" you mean someone who relies on automatic updates and doesn't look at what's getting installed. Which is fine, but if you're allowing automatic updates, you have to understand you're giving up the ability to catch stuff like this before it happens. (This situation could certainly be improved, but generally that's the state of things right now.)