Which would only happen if you didn’t cleanup your first flatpak experiment.
You think you did - but no you didn’t…
Your problem originates
- activating flatpak
- installed an application
- decide to remove flatpak but forget to cleanup
This will leave lingering software - always remove all flatpak resources before removing flatpak support.
TL:DR
flatpak list
flatpak remove <pkgname>
flatpak remove --unused
sudo flatpak repair