There is a bug in the september cumulative (security-) update for windows server 2016 1607 that cripples the ability to pre-set security options using GPOs. Microsoft is aware of the problem and there are two workarounds mentioned.
So this year I decided it was really about time I applied for the
@vExpert subprograms, and guess what! I'm in! So Thanks to our Programme Manager @vCommunityGuy and Sub Programme Business Units!