Twice it happened in my current game. The first time I was not sure, now I am:
I try to revoke a vassal title. He refuses and go to war against my rule. I win the war: not a white truce, I win it. Next the guy is jailed, I want to revoke and the possibility is greyed out: "must have a special revoke reason if we have a truce".
WTF? I went to war because he did not comply, he capitulated but, still, I'm stuck. Basically, totally loosing the war is a win for him.
I try to revoke a vassal title. He refuses and go to war against my rule. I win the war: not a white truce, I win it. Next the guy is jailed, I want to revoke and the possibility is greyed out: "must have a special revoke reason if we have a truce".
WTF? I went to war because he did not comply, he capitulated but, still, I'm stuck. Basically, totally loosing the war is a win for him.