The ends of walls are always square to the ref line.
As there is no trimming wall to the upper section then the wall will remain square.
You could add in a small return wall but you will have a similar problem.
The corner will now trim but the end of that wall will be square and not angled like your side wall.
The only other way I can see you get what you want is to use a hidden Solid Element Operation.
Barry.
One of the forum moderators.
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