Connectors with manual node edits should retain their shape
There is a problem which randomly occurs on some paths but not on others.
Generally this has to do with a line-only path, e.g. one that is not a
closed region. In some cases a path can become unstable, such that any
attempt to move that path causes it to collapse into a two-point straight
line. In the attached map, (a cut-down version of a much larger one) which
shows the area codes for the state of Missouri, if one attempts to move the
line between area codes 650 and 573, the line will "collapse" and lose all
of the intermediate points.
This problem has occurred with other paths I have drawn in which, for some
reason, the path can never again be moved or the path will collapse.