I have 3 monitors, 2 from the onboard intel and one from an ATI card with DVi connector using radeon opensource driver.

Under Fedora 24 all was good, with the 3rd screen working fine.

But under 25 and 26, the 3rd screen is just a mash of pixels. Doesn't matter which monitor I use for the DVI connection, it is pixellated, see
https://www.dropbox.com/s/57166j7nh6wmk ... .jpeg?dl=0 good screen is on the left. If I change the resolution on the right side screen via the monitors page in System Settings then I can see the pixellation change in response.

However if I take a screenshot, as far as Plasma is concerned it is OK, as per https://www.dropbox.com/s/ec4gqhgbkvtr6 ... h.png?dl=0 where you can see the green desktop on the monitor on the left move seamlessly into the default background of the monitor on the right.

I don't know if that is some weirdness to do with the stock Fedora background or something else. I can't change the background as to do that I have to right click on the screen and use the resulting GUI which I can't do for obvious reasons...

So... any idea what might be causing this?

Is there any way I can change the background on a given monitor other than right click in that monitor's desktop?

Any other ways to troubleshoot it and nail down the problem?

Zebee