Using either qvm-template or the Qubes Template Manager, I am able to see only the two templates I already have installed (on the command line that’s using qvm-template list). (This is true on my desktop system; my laptop works fine.)
I tried the --refresh option with qvm-template as well to try to “force” something if things were “stuck” somehow.
I’ve verified that /etc/qubes/repo-template/qubes-templates.repo is identical on both systems, so there doesn’t seem to be a problem with that file being corrupted on my desktop system.
This implies, of course that the same repositories are enabled in qubes-settings (since it actually modifies this file to enable/disable things); and that is the case (system templates and community templates only).
Is there some other piece of this puzzle I can check to make sure I haven’t somehow borked it?