Plasma Panel refuses icon placement

Help
1

I can create and place new plasma panels with no problem.

However the created plasma panel refuses to accept an application icon, somewhat inconsistently. My last creation accepted one icon and then quit accepting new icons.

I right click on desktop to select ‘Enter Edit Mode’

I left click on Application Launcher.
I select, click and drag an application icon onto the plasma panel.
However the plasma panel refuses to seat an application icon.

Am I doing something wrong?

I have been a KDE/plasma user for many years but processes have changed over versions and years.

Thanks.

Info
openSUSE Leap 15.5
KDE Plasma 5.27.4, frameworks 5.103.0, Qt 5.15.8
Linux kernel 5.14.21-150500.55.31-default (64 bit)
Graphics Platform: X11
AMD Ryzen Threadripper 1950X
NVIDIA GeForce GTX 1060
RAM 125.6 GiB

2

You are doing nothing wrong, but you can skip the “edit mode” step and just drag the application icon from the application menu to the panel.

Did you already try if this also happens in a freshly created additional user acount?

If it does you could consider updating your Plasma and Frameworks (and KDE Gear) etc. to the latest versions (works fine on one of my computers with openSUSE Leap 15.5):
https://en.opensuse.org/SDB:KDE_repositories