How dimension lines re-anchor to element snap points on reload
Learn how a dimension line keeps its attachment to an element's named snap point across reloads, and what happens when that snap point disappears.
A dimension line does not store coordinates - it stores which element and which named snap point on that element it is attached to, and re-finds that point every time the design reloads or the element recomputes.
If the snap point no longer exists (a classic case: a point on an arc, such as an arc's extreme point, that moved off the arc after the arc was reshaped), the dimension loses that attachment and will no longer resolve/update correctly after reload.