Corner wall junction with different heights causes accessory and schedule issues.

[Liamthanks]

I'm running some scheduling checks on a project of mine and noticed the surface area calculations were coming out incorrectly and I'm trying to work out why. During this process I noticed an anomaly with a wall accessory that seems to happen quite often when walls are different heights and after a manual check, I can see that the surface area calculations are excluding the wall end of the adjacent lower wall for some reason. Both walls are the same composite, have the same external surface and have the same junction order setting - the only difference is the height as one end is raked up.

Can anyone advise if there is a setting somewhere that I am missing that can clean up this junction so that it just wraps around nicely? 

Operating system used: Windows 6020 AUS