Ahh. I think I see your issue. It looks like your node is old? Our update server was migrated to the non-staging location and the URL was updated at the same time. The staging server stayed up and running for a while, but the recent Fedora Infrastructure datacenter migration caused it to go away and it’s no longer running. Most nodes should have updated by then, but it looks like yours didn’t. You’re running 9b322b9cead87ebf80881b75560e481b6e5a26966814b01bf0c12b61fa363708 from 31.20200323.3.2 (built on April 8th).
Have these nodes been powered down/disconnected for a long time or do you have automatic updates disabled?
The following should get you unstuck:
$ sudo tee /run/zincati/config.d/99-fixes.toml << EOF
[cincinnati]
base_url= "https://updates.coreos.fedoraproject.org"
# https://github.com/coreos/fedora-coreos-tracker/issues/481#issuecomment-653011069
[updates]
allow_downgrade = true
EOF
$ sudo systemctl restart zincati.service
The system will progress through updates (including a Fedora 32 rebase) and reboot a few times.