I generally use the command line. Also, I’m not running KDE, but I’ll try to help.
First look in /etc/yum.repos.d - you probably have a file named _copr:copr.fedorainfracloud.org:group_kicad:kicad.repo along with other files for the basic system. The file I mentioned is what provides the KiCad nightly copr access to dnf. If you have other files in there that also reference KiCad, I could see where KDE might get confused. So please let me know if that seems likely.
Months ago we had to add an “epoch” number because of various naming changes, but I’d expect any well-behaved package manager to understand that as it is a standard rpm / dnf feature. Have you had this problem for a long time, or did it just start happening?
I’ll see if there are any debugging flags for the KDE app, but since I’m not running KDE it will be hard for me to experiment with it.