What's wrong with KDE?

Question

linux

For some reason, some windows do not work in KDE5. I first encountered this when I tried to create a room, but there was no particular need and scored. Now downloaded QT Creator opened and (see pictures)

spoiler

Сразу после открытия программы

После открытия терминала

Answer 1

Apparently, you have problems with displaying OpenGL applications, does compositing work at all?
You can fix the problem with the creator by disabling the welcome plugin (qtcreator -noload Welcome)
doc.qt.io/qtcreator/creator-faq.html

Answer 2

I can suggest putting a proprietary video driver. This is how my attachments behave on Windows, if there is no firewood.