I know this is an old thread but just wanted to give my input incase someone else does a search for this problem. I was having the same issues and not finding much luck on the forums. Through trial and error this is what I found out:
It has to do with the order that you draw your walls and phase them. You have to phase your existing wall as Existing prior to drawing the intersecting New Wall to make the Existing Wall display correctly in an Existing or Previou+ phase. Example: If you draw 2 intersecting walls in a view phased as New Construction and then set one of the walls to Phase Created: Existing, then the New Wall will appear continuous through the existing wall - and a blank gap will display on the Existing and Previous+ phases. BUT if you phase the wall as Phase Created: Existing PRIOR to drawing the new intersecting wall, then the existing wall will display as continuous - and the mysterious blank gap will NOT appear on your Existing and Previous+ pahses
+1 on this. I know this is an old thread, but after spending far too much time trying to make my things display correctly, this was exactly the issue. All existing walls must be drawn prior to any new walls, otherwise the new walls will interact with the existing walls in the existing only view. A large historic warehouse project I was working on where we knew the entire interior would be demoed- so didn't bother to model it at the beginning- about drove me batty trying to figure out why this was happening. Ended up drafting the existing walls that needed to show up as demo in the cd set since all the new construction was already modeled.
Thank you for the input. i'm wrestling with this same issue now. Isn't it a little stupid that Revit doesn't acknowledge the phase category that's built into the software, but rather acknowledges when the walls are drawn! is this meant to be fixed at some point?