When in Audacity and Virtualbox the Text cursor (I) has become weird. It looks like a little square surface, about 1 centimeter wide and high on my 24 " screen, that surrounds the real cursor sign and contains rubbish. Also the other cursor shapes are somewhat out of order. This bug appeared a couple of months ago, after an update, and I have waited for a new update, that would hopefully correct it, but that hasn't happened. I know a fresh installation of KDE Neon doesn't have this problem, but I want to avoid going through a new installation and configuration of everything to my satisfaction.
Created attachment 106927 [details] Mouse cursor issue
This is happening to me too after an update 2 days ago. It seems related to the hardware cursor back buffering. If I try to capture a screenshot with mouse cursor included, the issue can't be seen. The attached screenshot shows an unwanted rectangle displayed after I scrolled the list up. Needless to say this is seriously annoying and it happens constantly, on every mouse move Dell Inspiron 15 7000 series. Nvidia GeForce GTX 960M card. KDE Neon 5.10. Plasma 5.10.4, Frameworks 5.36.0, Qt 5.9.1, Kernel 4.10.0.
Created attachment 106928 [details] Beautiful KDE
Created attachment 106938 [details] With mouse cursor
Been able to capture a full screenshot with mouse cursor. I was just Alt-tabbing between windows
Video driver issue. Please report it to the bug tracker of your video driver vendor.
Gnome works perfectly. Same computer, same video driver.
Does disabling compositing (Alt+Shift+F12) or using the XRender compositing in KWin instead of OpenGL compositing make any difference?
No need to answer, it was already investigated by KWin developers, see bug 382812.