Interesting. In 2016, when I filed
Bug 1397174 dnf history undo doesn't work even with keepcache=1 *
https://bugzilla.redhat.com/show_bug.cgi?id=1397174
the recommended workaround was to install the 'local' dnf plugin (package:
python3-dnf-plugin-local).
Installing the local plugin is still a good solution. It will make undoing transactions
work even for 3rd party repos.
* The title of that bug report was subsequently changed.
Robin