I've solved the issue. Seems like new KDE has two ways for 'run' menu actually 'Command run' and Krunner. So the first one probably introduced recently and stole keybinding from Krunner! If you change it to Krunner then it will work as before (just look for run Krunner keybindings)
Broken here after 19.10 to 20.04 upgrade.
Perhaps there is a problem with some automatic upgrade process.
Running the following fixed it for me:
Sources:
https://bugzilla.redhat.com/show_bug.cgi?id=1781054
https://bugs.kde.org/show_bug.cgi?id=413368
I've solved the issue. Seems like new KDE has two ways for 'run' menu actually 'Command run' and Krunner. So the first one probably introduced recently and stole keybinding from Krunner! If you change it to Krunner then it will work as before (just look for run Krunner keybindings)