Apps appear to fail the installation but get listed in my Start Menu and subsequently load. Where does that leave me as a newbie user? Am I supposed to ignore the 'failed installation' message and hope for the best? Or do I need to spend time testing every feature of an app before I can trust that it was properly installed?
We had another user unable to install something from the software store recently with the same error when trying to install Windows App Support; some of the dependencies did this to them.
Not saying this will fix the problem, but we typically recommend people to switch their download server to "Main Server" in software & updates configuration.
This could be because of different Package Formats. So, one could be the APT Package and one could be a Flatpak or a Snap.
It seems that this could be a Problem with the Source Server I would think. Like @StarTreker already showed, You could try to set that to ''Main Server'' or at least to another local Server if available.