They’re the same version, only package name and the java security provider differ. I want to make sure if they’re using any word filter.
You may have already installed the newer version of F-Droid, which must be uninstalled first; I don’t know if F-Droid opts in to have an option to keep app data.
You need to disable some strange setting in developer options. Its called “system optimization”. That basically blocks side-loading… At least on my HyperOS device it was like that.