Sorry if I wasn't clear before. But I think you have to move the historian onto blessed blood. It sounds like there is an order of operations issue. Did you do it in this order: (1) create blood surface (2) bless blood surface (3) move historian onto blessed blood. If you take these out of order, for example by having the historian in the blood before it is blessed, it doesn't trigger properly. This is because most surfaces a triggered by moving onto/in them by walking or teleporting. Similarly, if you bless the historian and not the blood it won't work. If you did it in the order I described and it's still not working, then it is definitely a bug.
