Last week, I took a look at fixing Fedora 30 GNOME Software to get Silverblue 30 to 31 distro upgrades working. The fixes are now available in F30 updates-testing (gnome-software-3.32.4-6.fc30), backported from upstream git.

Check out my YouTube video where I go in more details: https://www.youtube.com/watch?v=t_7jtwfnZkQ