Allegedly, on or about 31 October 2017, Jon LaBadie sent:
Your problem seems similar to what I experienced early on with F26.
I normally run Mate and Compiz. In my case the culprit seemed to
be Compiz. If I selected a different window manager the problem
did not exist.
A Compiz update or 2 later eliminated the problem for me.
I'm running Mate without any special effects. So how much of Compiz
comes into the equation, I don't know. I have been keeping fairly up
to date (every few days or so).
Ed's advice about how to set a Nouveau vsync option has done the trick.
I'm yet to give it a serious test, such as watching a long video clip
with lots of motion in it, but haven't noticed the issue recur with
[tim@localhost ~]$ uname -rsvp
Linux 4.13.5-200.fc26.x86_64 #1 SMP Thu Oct 5 16:53:13 UTC 2017 x86_64
Boilerplate: All mail to my mailbox is automatically deleted.
There is no point trying to privately email me, I only get to see
the messages posted to the mailing list.
Moments after you've soldered the wires onto the plug just perfectly,
you'll realise that you forgot to put the backshell on.