Oh gosh, I have no idea. I don't even understand what flatpack is. Or YaST either!
However, I'll investigate and try to get an answer for you.
Oh, look what I found on the download page
For issues that are related to the Flatpak packaging, you can contact the author via the repository at github.
So you can make a new Issue report there. Do you know how to do that, or do you need more detailed instructions?
Will you let us know what you find out? If it's a common problem, we might be able to help other users.