On Monday this week I spent about 4 hours cursing at elevation tags in Revit. Last I recalled, an elevation tag in Revit is supposed to update to reflect the detail and sheet info once placed on a sheet, no matter what. Well, not this time. I could change the detail number in properties for the elevation and it would show on the sheet and in properties as having updated, but the marker itself would not update. Steve Stafford posted a great video showing this. Steve S. found that changing the elevation type would cause the marker to update and display correctly.
I also found that the marker would resume displaying updates to the detail number on a consistent basis provided it cut building geometry. If the extents of the marker view depth did not cross any geometry, it would not update the detail number if updated. So, another temporary solution would be to ensure the depth of the elevation view touches or cuts through building geometry. However, I haven't had a chance for successful testing to ensure this is the case. Like Steve S., I too am on WU2, so I'm curious if others are experiencing this under WU1 or if on WU2, if you can verify that cutting geometry ensures the tags update correctly.