https://bugzilla.kernel.org/show_bug.cgi?id=204849
--- Comment #3 from Justin Clift (justin@postgresql.org) --- As an extra data point with this, the error in my case only happens when I have an external monitor plugged in via the HDMI port.
This is on a laptop, with the error not showing up if only the in-built display is in use. eg the HDMI not even plugged in.