Lost my capital when an A.I formed a kingdom

[ChaosIncarnate]

so while playing my first playthrough of the charlemagne dlc i managed to create a new custom kingdom as a Slavic ruler and everything was fine for the 1st 200 or so years then out of no where the king of rus dies and his land gets split between his sons, one of the sons forms the kingdom of ruthenia and becomes independent when this happens, every single time my capital Kiev "Magically" becomes his. Kiev has no Claimants since its been my capital from the very start so im assuming this is a bug a rage inducing bug.

 

[ChaosIncarnate]

here's a link to the saved game before the king of Rus dies (i can't upload it here as its to big) https://www.dropbox.com/s/nmivq6xsjppjkcv/Ironman_KingdomCome.ck2?dl=0

 

[Da9L]

Thanks you for the report!

I can understand that this is indeed a rage inducing bug. I have relayed this issue to the devs.