Comment # 11 on bug 69076 from mike@mgoodwin.net

I've seen elsewhere and confirmed for myself (I'm reviving an old laptop today)
that you need to use EXA acceleration and add "EXAPixmaps" "on" in the Devices
section.

Option "AccelMethod" "EXA"
Option "EXAPixmaps" "on"

and the problem disappears. Don't even attempt to use glamor, it doesn't work.