Comment # 6 on bug 1117833 from Neil Rickert

I can confirm this problem.  I have been noticing it for some time, though I
never thought of reporting it as a bug.

I mainly use KDE, and I don't think I have ever seen it happen there even with
Plasma Wayland, though I suppose I should recheck.

When I use Gnome, I always see this happen.  I have only seen it once per
session, at perhaps 2-5 minutes into the session.  When using Gnome, I normally
use Wayland.  I don't recall whether I have see it with Xorg.

When I have seen the problem, it has always been in an "xterm" which is my
preferred terminal emulator.  I do have an "xterm" starting as an automatic
startup program when I login.