copyq problems

In you have linux, flatpack installation of copyq can solve many possible problems, but it has also some disadvantage.

The best choice, then, is to install copyq according to its website:

Ubuntu and Debian users can add the official PPA:

sudo add-apt-repository ppa:hluk/copyq
sudo apt update && sudo apt install copyq

In same cases it could be not enough the above code. Then you can try with something like:

QT_QPA_PLATFORM=xcb copyq

You can set permanently in KDE menu with a config like in the below image