Comment 1 for bug 1704484

I think the Epoxy support should be enabled.

4.3) VSYNC and tearing
======================

Starting with version 4.13, xfwm4 now supports VSYNC via two different
method, either using OpenGL or the Present X11 extension.

xfwm4 relies on libepoxy for OpenGL, and on libXpresent for Present support.

Support for those features can be checked using "xfwm4 --version":

 Build configuration and supported features:
        ...
 - Xpresent support: Yes
 - Embedded compositor: Yes
 - Epoxy support: Yes
        ...

If both VSYNC methods are available, xfwm4 will prefer Present over OpenGL.

from https://git.xfce.org/xfce/xfwm4/tree/COMPOSITOR