Chamfered shower walls not rendering correctly. Wrong angles wall intersection?

[divreig]

Working on a chamfered shower looks like the walls are poking through at angles. Cant seam to figure out how to get this to just cut them at 90. Looks strange. any one how to correct this? See attached pic. 

Proposed.plan

[Kbird1]

3 hours ago, divreig said:

any one how to correct this?

 

The Angled wall is messed up it seems and they are all facing the wrong way so I 

1. copied Door to another wall temporarily
2. deleted angled wall ( and existing door)
3. reversed the two remaining walls and rejoined on 45° angle using diamond extend handle
4. copied door back into angled wall.
5. At least I think that was all the steps....

* I don't have X11 installed so I had a look with X13