<p>After a strange unnamed window appeared on my desktop, I used
<code>xprop</code> to identify it and a search lead me to
<code>xwaylandvideobridge</code>.</p>
<p>From the man page of</p>
<blockquote>
<p>xprop - property displayer for X</p>
<p>SUMMARY<br />
The xprop utility is for displaying window and font properties in an X
server. One window or font is selected using the command line arguments
or possibly in the case of a window, by clicking on the desired window.
A list of properties is then given, possibly with formatting
information.</p>
</blockquote>
<p>From <a href="https://github.com/KDE/xwaylandvideobridge">GitHub KDE
/ xwaylandvideobridge </a></p>
<blockquote>
<h2 id="about">About</h2>
<p>By design, X11 applications can't access window or screen contents
for wayland clients. This is fine in principle, but it breaks screen
sharing in tools like Discord, MS Teams, Skype, etc and more.</p>
<p>This tool allows us to share specific windows to X11 clients, but
within the control of the user at all times.</p>
<h2 id="how-to-use">How to use</h2>
<p>xwaylandvideobridge should autostart on login. It will run in the
background. Next time you try to share a window a prompt will appear.
The previously selected window should now be available for sharing. The
title will always be "Wayland to X11 bridge" no matter what window is
selected.</p>
<p>The system tray icon provides finer control.</p>
</blockquote>
