For anyone is struggling to find Caleb for the first time,I solved the problem apparently it is in the Full moon event idk if you need to do all the quest but i finished them anyway.After finishing the Full moon (mine is the logan werewolf route so mine last quest is 'talk with logan and ask him how he feel after antilycan treatment')and Caleb part will appear(you need three hearts with Bernard but I only have 1 but it still works)so ya , I hope this helps 🙃(and im sry if i spoiled anything)
Sorry if my comment didn't help. I thought that, in order to make the second expansion of Bareshade, you needed the fourth heart with Bernard, and in order to start the Bareshade expansion you needed his third heart. Every time that I visited Bernard by night to obtain his third heart the werewolf attack triggered, so I wrongly assumed you'd already completed that part.
I assumed that you knew, but now I'm not sure: do you know that in the game there is a questlog by clicking one of the icon in the bottom left and after in the top left?