Land transferred to a fellow king-tier vassal with no input and no info on why it happened

[Jespoke]

Information​

I have verifed my game files (Steam only)​

Yes

I have disabled all mods​

Yes

I am running the latest game update​

Yes

Required​

Summary​

Land transferred to a fellow king-tier vassal with no input and no info on why it happened

Description​

* Note, i have none of the DLC *

I hold the Kingdom of Frisia. I am a subject under the Emperor of Francia. The King of Francia is a separate subject of the Emperor of Francia.
I hold the Duchy of Flanders, which De Jure belongs to the Kingdom of Francia. One day out of the blue, all my counties and vassals in the Duchy of Flanders belong to the King of West Francia. I still hold the Duchy title until it is destroyed on the month tick.

Our liege did not just lose a war, it in fact happened while they are in the middle of a war.

I don't know wherein the bug lies. There are at least two options:
* The land was transferred by a bug.
* The land was transferred by some legitimate way, but whatever event/textbox/anything that was supposed to inform me of it did not show up.

Steps to reproduce​

I don't know what happened, but i have attached before and after saves.

Game Version​

1.11.1

Platform​

Windows

Additional Information​

Affected Feature​

• Gameplay

Save Game​

View attachment Dutch_after_backup.ck3View attachment Dutch_before_backup.ck3

Other Attachments​

 

[Jespoke]

I ended up finding out why the land got taken: It was a claimant faction that installed the King of Francia that took the land. I don't know if it is intended for that to steal land like that, but if it really is, it should inform you when it happens.