Strange behaviour of title 'kingdom of the fylkirate' on destruction

[herzog-leto]

First of all: Hello and thanks for reading.

In my last playthrough I've noticed something
strange if you play as nordic pagan and managed
to create the empire of the fylkirate.
Consider following setup (or go straight to tldr;)

Starting in 769AD as nordic tribe with unreformed germanic religion
you first reform the faith an become reformed germanic.
On doing so you gain the titular title 'the fylkirate' witch is
a duchy tier title. Additionally you become the fylkir; head of
the organized germanic religon.
Then you switch 'the fylkirate' to be your main title
and grow your realm in size until you can use
the intrigue option to form a new kingdom.
At the same time you work your laws
up to absolute tribal organization to adopt fuedalism.
On creation of the kingdom of the fylkirate all
dutchies completely controlled by you or your vassals will
immediately become dejure titles within the new kingdom.
Those titles will be removed from their prior dejure kingdoms
and empires as well.
Grow your realm further until you can use the intrigue option
to create a new empire. You'll finally end up with the
empire of the fylkirate. You still own the kingdom and dutchy tier title.
The kingdom title wont be dejure part of your empire.
Wait for 100 in game years to dejure shift the kingdom title
to become part of the empire.

tldr;
You own both the empire and the kingdom of the fylkirate.
If you destroy the kingdom of the fylkirate it can never be created again
but it is still listed as dejure part of the empire.
If you save and load your game and then go to your dynasty overview you will
notice that all rulers that were formaly known as 'fylkir XY king of the fylkirate'
are now simply known as "fylkir XY" and that the golden circle around their
portrait will be gone as well.
If you hover over the the total prestige of your dynasty in the dynasty overview
you can see that prestige from the falkirate kingom is oviously not totaled
into your dynastiy prestige.
I think your total prestige (top right on mainscreen) will also drop
(but I can't confirm this because: ironman)

My questions here are
- can anyone confirm or falsify this?
First I thought my installation might just be corrupted.
But i happend twice (both iron man vanilla allmost every dlc)
- If anyone can confirm: is this realy intended or possibly a minor bug
- If it is a bug: is it known? Where can i look it up if it is know?
- If unknown bug: is it even worth to file a report and where to do so?
I realy can live without the kingdom title -
it's just sad that all those great kings are now known as mere dukes :P

Answers are well appreciated.
And again thanks for reading / spending your time on this.
Best regards ringmoe


PS: Since I'm no native english speaker: be gentle about my spelling and grammar