OS: Fedora Linux 40.20240130.0 (Kinoite Prerelease) KDE Plasma: 5.92.0 in the onboarding wizard on the section "here are some cool apps you get in Discover" the links dont work. They open the "plasma-discover-rpm-ostree" specific "info about this OS page, instead of launching the appstream link. I added the --user flathub repo. as far as I understand it should launch a specific appstream link that opens the flatpak. this may be an issue in the plasma-discover-rpm-ostree package
This does sound like it's an issue with how appstream:// links are parsed in the distro, yeah. Maybe they're set to open with the wrong app by default. I'd recommend following up with them first in the absence of any indication that Welcome Center is doing anything wrong.
https://bugzilla.redhat.com/show_bug.cgi?id=2263744