Does anyone knows how to fix this?

Down/Left/Right Arrow keys are working fine.
Up/Down/Left/Right Arrow keys of the numpad works fine too...

The Up key that it is not working inside KDE Plasma Desktop, is working fine in a pure terminal (alt+ctrl+F1 for example)!

So I guess that it is a configuration (that I changed by mistake???) in the workspace!

Anyone has a clue?

Thank you!

I renamed the ~/.kde directory to start with a fresh config, and all of the arrow keys works fine!

So it has to be a configuration issue!

In your old configuration, verify that your keyboard layout has not been changed in System Settings.

bcooksley wrote:In your old configuration, verify that your keyboard layout has not been changed in System Settings.

hmmmm

I did not have any keyboard layout at all.
I checked the "configure layout" and now it is working fine again!

I am not sure that this was the root of the problem though...
Anyway, now it's gone

Thank you!