This is an issue I've had for years. Never really tried to find an answer before.
Lets say you made a square- then you angled it. After you angle it you want to adjust it one way. So you try to adjust it. aaand it distorts. this serves no purpose at all. Is there a setting that will make it work in a sane manner? CAD programs do it correctly, why not Corel?
If the shape is not a "Rectangle" but has been converted to be a Curve shape, then you could:
That allows freehand adjustments, but not precise dimensions. For that, see Ronny's comment about the Coordinates docker.