why is there only one join option available?

[kgatzke]

Why is there only one join option available between these two walls?  I tried extracting them from the project, deleted all the design options, wall sweeps, hosted components, top and base extensions, made them identical in every way and still could only get one join.  Newly created walls join either way but not THESE two.  I made identical walls in the project and they initially joined the way I wanted, but when I moved them into the correct position the error reappeared, if that's any clue as to what's going on. 

I want to understand what's happening here and not try to use some work around to fix the problem that will only cause more problems somewhere else.

edit: r2019 by the way

[barthbradley]

I think Revit is doing a pretty good job considering the "gnarly" condition. I mean you got different wall types, overlapping walls, an in-place void cut and a profile edited wall all coming together in one intersection.  

...here's ones gnarly example in the mix of gnarlies: