Reports "Operating System Updates Unavailable"

This had been reported downstream in Silverblue:
https://github.com/fedora-silverblue/issue-tracker/issues/257

When I start gnome-software in the Updates page (gnome-software --mode=updates) I see there that banner too, but it vanishes a second later. It can be due to gtk4's "show widgets by default", at least in my case.