walls don't join properly

[Anonymous]

Recently, I began to have issues that walls don't join properly, I tried wall join setting to allow join but it didn't help. Please see the attached image. Especially I don't understand why there is a dash line at one end of the wall. 

[barthbradley]

...Are they the same height?

...Is Automatic Join enabled? 

...Are the Wall Layer Functions different? 

Try different Joins using the Wall Join tool on the Modify.  Try tapping on the Blue Dot at the ends of the Walls.  Some Join conditions require finessing.  

Specify Wall Join Cleanup Options: 

https://knowledge.autodesk.com/support/revit-products/learn-explore/caas/CloudHelp/cloudhelp/2015/EN...

About Applying a Function to a Layer of a Compound Structure: 

https://knowledge.autodesk.com/support/revit-products/learn-explore/caas/CloudHelp/cloudhelp/2016/EN...