The Properties sidebar at the right, does not contain the Connector properties when a Connector is selected. It does contain the Line and Position and Size properties of the Connector, but not the Connector... properties (like Type) that you see when you right click a Connector in a drawing.
On one hand, it isn't possible to add connectors in Calc (bug 79356), on the other, indeed there is no sidebar panel for connectors in Draw, either, thus I'd consider this a duplicate of bug 97889. *** This bug has been marked as a duplicate of bug 97889 ***