The event hold_court.6060 has a courtier offer to buy a holding from you to build a castle and become a baron-tier vassal. Right now, the event can fire for settlements in the colonization process. I imagine things will get weird if a castle with a baron exists in a secondary holding and then the colony fails and returns to Tom. This was reported over a month ago on the Discord (https://discord.com/channels/751097183448727552/1208077605677309972). I ran into it again myself just now, so I guess it was never addressed.
The event
hold_court.6060has a courtier offer to buy a holding from you to build a castle and become a baron-tier vassal. Right now, the event can fire for settlements in the colonization process. I imagine things will get weird if a castle with a baron exists in a secondary holding and then the colony fails and returns to Tom. This was reported over a month ago on the Discord (https://discord.com/channels/751097183448727552/1208077605677309972). I ran into it again myself just now, so I guess it was never addressed.