This is my one main complaint about Fedora Linux.
Looks like flatpaks updates
Discover checks knewstuff (global themes, plasmoids, etc.), Flatpaks, firmware and snaps, (which all have a relevant backend package something like (discover-backend-packagekit). Discover, well more like PackageKit, will let you know if a reboot is necessary if there’s something like a kernel update.
I had reverse situation, discover said there’s none of apps i need or/and updates, while dnf was working flawlessly
Try this: “sudo dnf update ; sudo flatpak update”
pkcon refresh