Looks like this is several years old but I just got this same problem going on in 2012. I have been working with a template started OOTB - not brought up and updated.
I have not seen these corner issues before. Any ideas????
First pic - shows dots - existing phase in view set for existing
Second pic - demo phase - parts demolished - not entire wall - view set for Demo
Third pic - new phase with view set for new
Only the existing shows this but I also get this problem if I draw a wall in the new phase using a view with new phase settings. So if the wall is created in the view phase - I get a dotted corner.
I see your wall projection line weight is set to 5 in object settings. If you lower that to 1 the dots disappear. The componant line weights are still there. I am not sure what element is actually making the dots but the line weight is controlled by the Object styles projection line weight.
But the office standard has the core of the wall much thicker than the other layers. SO, setting the number down does make it go away but I want it fixed - not ignored.
Know what I mean???
The problem is being caused by the Projection line weight value for walls exceeding what you have set for the non-structural components of walls. That is, since the non-structural components of walls are set to have a cut value of 2, any Projection lineweight that exceeds 2 results in the "dots" which are actually just the intersection of the wall boundary lines at the corners of the wall. I'm not sure these aren't overridden the same way as the internal components, but that's the way it works. You might want to submit a service request or wishlist item on this one, because I don't see any way around it. As far as I can tell, your only option is to model them as separate walls (core wall vs. finish wall) and use filters to override the graphics.
Hope that helps.