Yes, I read all of that. Packagekit is installed, but gnome-packagekit wasn’t installed originally. They said they had to uninstall that, but either way none of their suggestions have any affect on my problem. Not sure what you mean by “source repository”, this is just in the regular openSUSE repositories. If they weren’t enabled I couldn’t install anything.
As I mentioned in the original post, I have tried that, and deja-dup does the same thing it does when duplicity is installed. It asks for my password, runs for a minute, then asks for it again. No matter how many times I participate in thr loop, it results in no change.
I do not know that it works. My experience with flatpak has ranged from terrible to functional but not great. Usually, if I cannot find a program I want to use with zypper, I consider compiling it myself before using flatpak.
Since you are using it, can you tell me if the flatpak version at least recognizes your previous backups?