https://lkml.org/lkml/2017/12/7/201 tries to raise the limit, but according to
https://bugs.freedesktop.org/show_bug.cgi?id=102508#c11 it does not work.
Also, Skull Canyon is 6th generation, is it not? See
https://www.intel.com/content/www/us/en/nuc/nuc-kit-nuc6i7kyk-features-
See also similar bugs
https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1776260
https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1714178
Those were treated as if the 8kx8k limit was ok, and the bug was in the
compositor
which failed to work around that limit. Perhaps this bug
Did this issue start happening after an update/upgrade? Was there a
prior kernel version where you were not having this particular problem?
Would it be possible for you to test the latest upstream kernel? Refer
to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest
v4.17