I tried something else : I declared war through the diplomacy window, and it worked as intended, no sov teleport.
I also got a "weak" version of that bug. Sometimes I tell my sov to get out from a city. He disapear, then I click next turn and voila ! He's here.
Another similar problem : when I attack a city, get defdeated, my sov is teleported in my nearest city : I can see the shield. But ! If I tell him to get out, then he travels from the city he was defeated to the rally point near the city he was stationed
. After that I have just one sov and everything works as intended.
Is the trait "madness" already implemented ? 