Hi Malcolm,
I have disabled fastboot support in Bios. I had double boot. But after 3 years I'm confident i SUSE now. :-) and since version 15 it is really a step ahead - works better than Windows.
Now I change my Server to Linux as well.
I learned the options of Bash and Linux....
------- X-Window-------------
I think because I get to login window, can login, but the Desktop do not start. And here X-window starts I think. I had in past some issues with x-windows.

hans-christoph@linuxSLED:~> echo $XDG_SESSION_TYPE
hans-christoph@linuxSLED:~> /sbin/lspci -nnk | egrep -A3 "VGA|Display|3D"
00:02.0 VGA compatible controller [0300]: Intel Corporation Skylake GT2 [HD Graphics 520] [8086:1916] (rev 07)
	Subsystem: Fujitsu Limited. Device [10cf:18d1]
	Kernel driver in use: i915
	Kernel modules: i915
00:13.0 Non-VGA unclassified device [0000]: Intel Corporation Sunrise Point-LP Integrated Sensor Hub [8086:9d35] (rev 21)
	Subsystem: Fujitsu Limited. Device [10cf:18d0]
	Kernel driver in use: intel_ish_ipc
	Kernel modules: intel_ish_ipc
I can't interpret what this means.