When I click the wall it doesn't activate the temporary dimensions for me to adjust the dimension . I have checked the constraints by reavealing constraints and that is not the cause of the issue. The file is attached for perusal .
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When you select a wall, have you check "activate dimmensions" in the left upper corner?
Is the dimension to the left of the wall (near the top of the stairwell) one that was a temp dim and you made it permanent? Because it is connected to the wall in question.

Activate Dimensions. (Options Bar)
Note: At a certain point, Revit will stop showing temporary dimensions automatically to conserve resources.
....this explains why:
I think it depends on the selection. Example below showing two families in the same file, one needs to activate dimension and the other does not. I still don't know why.
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