> Working with both Fedora 25 and 26 last week, I noticed
> that if I copy something to the clipboard from a program
> and then exit the program that the clipboard is not lost.
> Yippee! That X11 "feature" drives me nuts!
Are you using a clipboard application like clipit or xcfe4-clipman? If
so, you usually can adjust that behaviour there.
Cheerz,
Lars