Yeah, so I converted an enemy vassal into my house, then I gave him a fief. This fief became part of my House (House Forkwood) and then, when I went to the fief it gives me an option to besiege the castle, and no option to enter the hall or anything like that. Also, when I talk to my vassal it gives me an option "I would like to make peace with House Forkwood" which is my own faction. So if there's anyway to fix that, that would be great.