kde – Super key stopped opening the start menu


After a casual reboot, the super key no longer causes the start menu to pop up.

How do I turn it back on?

Operating System: Kubuntu 19.10
KDE Plasma Version: 5.18.3
KDE Frameworks Version: 5.67.0
Qt Version: 5.12.4
Kernel Version: 5.3.0-45-generic
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-7700HQ CPU @ 2.80GHz
Memory: 15,5 GiB of RAM