Pretty sure this is related to the handling of the attach-node setup at the plugin level; need to determine when each 'module' should handle attach nodes rather than allowing both modules to handle them.

It seems likely that the 'top' module is creating a second attach-node when the docking ports node is occupied (or vice-versa, docking port creating a duplicate node).

Will need to dig in and find the best steps to duplicate prior to investigation for fixing the problem.