Explain how this war ended

[Verdiss]

So here I am, ruler of the Byzantine Empire. Things are going well, but one of my least favorite vassal queens (who I had foolishly granted the kingdom rather than making a viceroyality, because I didn't know that was a thing at the time) is getting unruly. I have righteous imprisonment on her, I think due to a plot, so I try to imprison her. The imprisonment fails, and she revolts. Well, fair enough, I can crush her in less than a year! Then, a week later, the war ends, the kingdom becomes a fully separate realm, I lose a good portion of land. Now, my first thought was the rebelling queen died, somehow invalidating the war, but she was still alive and kicking, although for some reason no longer queen. I checked the history of the kingdom title, and it said nothing about how the title had been transfered. I simply cannot wrap my head around why the war ended and the title was transferred, and it is very frustrating as now I have to eat the new real county by county to restore my old borders. Does anyone understand what exactly happened here, so I can avoid it in the future?

 

[Dryhad]

You say the kingdom changed hands, who holds it now? Are they your vassal? Were they the queen's vassal at any point?

 

[DorlasAnther]

Bug. Revolts aren´t ever supposed to become independent realms. Offer her vassalization, switch to her and accept. Or give yourself strong claim for that kingdom and conquer it.

 

[Aardvark Bellay]

Some faction or council action of her revolting realm deposed her. Saw that too several times.
Sometimes on the losing side just before a war could have been over.
Anyway, there are some weird issues with deposings on 2.5.2.
I don't think that should happen.
So yep, bug.

 

[Rationalsanity]

Things like these are why I will never touch Ironman.