If I interact with public noticeboards like the one next to the Bank in the Quartier Publique it will often fire me into the conversation when someone else interacts with it - assuming I'm close enough.
This latest incident happened as follows: I interact with the board, close the conversation. RP a bit. I transition to the Marchand and back, using the board there briefly. I come back and stand near the Publique board and a PC walks up to it, uses it, and the conversation fires for me.
Deeply annoying!