OK. I played with the Fedora templates more and finally got this working.
This will work in Debian templates, but not Fedora.
In the Fedora templates I go to /etc/yum.repos.d/ and edit all of the *.repo files.
Uncomment #baseurl=http://download.example/... and replace that with something like baseurl=http://HTTPS///download.fedoraproject.org/
Comment out #metalink=https://mirrors.fedoraproject.org/...
I don’t know it this is overkill, but in the .repo files where there was a baseurl already with http://, I changed all of them to http://HTTPS///
I cloned a few of my existing Fedora templates and tested this out and it appears to have worked every time.