These are two walls I did not draw. Still one is concrete and the other is the insulation. In any case the insulation appears to be on the top of the concrete one and this is exactly the opposite i want to see.
Check the strength of the building materials used in the walls.
Stronger building materials will trim weaker ones - but I don't think that is the issue here.
Display order will affect the plan view of 3D elements - including walls.
So you should be able to send the insulation wall back or bring the other wall forward.
You will see the line along the joining length will belong to one or the other wall - depending which is on top in display order.
Currently your insulation wall is above the other wall in display order - hence the thinner joining line between the two walls.
The thick end line you have circled is because the insulation has no end lines at the moment.
If it is a composite wall, you can turn on the end lines in the composite settings dialogue.
If it is not a composite or that did not help, then in the floor plan display settings for the wall you can turn on the end lines (usually this is on by default).
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