I suspect it actually is the connector... at least some artifact of the connector.
I.e., if you go to the Display tab of the Properties Palette.
At the bottom , click the Select Component button, then click on the dot, I suspect that it will select the Connector Display component... which, typically by default, is turned off.
This dot is placed according to the connector position defined in the style. I.e., if you modify those values, the position of the dot moves. What is odd, however, is that the position of the dot doesn't scale according to the drawing scale nor the annotation plot size.
Martin Schmid
Product Line Manager
Mechanical Detailing and Electrical Design
Architecture, Engineering, and Construction
Autodesk, Inc.