KDE Plasma desktop not recognizing screen edges

Question

I love plasma (5.8.3 Neon on a Samsung rf711), but my desktop behaves like I have another monitor to the right of my screen. My windows and mouse could disappear into this imaginary space. Is there a setting I'm missing?

Answer 1

Whatever is happening on your system is not normal behavior, and I can't replicate it. Just shooting in the dark, here are a few things to check, which will at least rule some things out.

As a first step, there are two places to check in the System Settings.

Display and Monitor:

Click on Multiple Monitors and verify that it doesn't think there is another monitor there.

Workspace Behavior:

Click on Screen Edges. The monitor image has a button at each corner and in the middle of each side. If you click on one of those buttons, a popup menu appears with settings for that portion of the screen edge. I haven't explored the effect of every setting, but No Action should result in the cursor not doing anything unexpected at the edge.

Panel:

One other possibility I can think of to check -- the edges are standard places to park panels and widgets. Cursor off to the right, then right-click. See if anything pops up in the way of a settings screen, which might identify something hiding on the side.

Desktop Effects:

This might help identify where the cursor actually is if it is still on the desktop when it appears to be somewhere else. Again from the System Settings, click on Desktop Effects. Select the All Effects tab. Near the top, in the Accessibility section, is a feature called Track Mouse. Enable this.

If you click on the wrench symbol, you can see the default key combination to trigger this feature. On my system, it's Meta + Ctrl ("Meta" is the Windows key or the equivalent on a Mac keyboard). When you can't see the cursor, pressing this key combination will produce a locating pattern around the cursor, which you will see if the cursor is hiding on the desktop.

Answer 2

This solved for me although I had to switch on a tv that's connected but hasn't been on since reinstalling the operating system. A better result than expected was obtained by figuring out what it was trying to do when the cursor vanished off to the right, and then I clicked and dragged the image of that second screen in monitor settings & repositioned it to represent where it physically is in the room. So, now when the cursor vanishes off the appropriate edge, it appears on that screen as a preference - effectively whistling up an instant 55" parking monitor in the process :)