When you have two panels, one placed on the bottom of the screen and one placed on the side of the screen (e.g., to the right), it becomes impossible to edit the side panel because its buttons get covered by the other panel.
STEPS TO REPRODUCE
1. Put one panel to the bottom of the screen (you probably have one already) and another one on the right side of the screen.
2. Try to edit the side panel
Realize that you cannot because the "More settings button" gets covered by the bottom panel.
The side panel editing buttons should be arranged so that they do not get covered by the bottom panel.
Linux/KDE Plasma: Kubuntu 19.10
KDE Plasma Version: Plasma 5.18
KDE Frameworks Version: 5.67
Qt Version: 5.12.4
Created attachment 126106 [details]
Screenshot of the problem
Operating System: Arch Linux
KDE Plasma Version: 5.18.0
KDE Frameworks Version: 5.67.0
Qt Version: 5.14.1
Kernel Version: 5.5.4-zen1-1-zen
*** This bug has been marked as a duplicate of bug 417523 ***