Thank you very much for this report. It does indeed seem like Model Center does not properly render redeclared connectors inside components. It is something we will look into.

As a work-around you could create multiple versions of your component class with different set of connectors, and make the instances of the component class replaceable. Not sure if this would be an acceptable work-around for you, but it should work.

Another way of increasing the chances of getting an answer is to provide a complete example of the problem. I'm assuming you are meaning something like this:

package ConnectorsTest
  partial model GenericFlow "Flow Template with replaceable ports"
    replaceable FlowPort portA "Flow from/to Stock A" annotation(Placement(visible = true, transformation(origin = {-66.537, 24.02}, extent = {{-10, -10}, {10, 10}}, rotation = 0), iconTransformation(origin = {-100, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
    replaceable FlowPort portB "Flow to/from Stock B" annotation(Placement(visible = true, transformation(origin = {110, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0), iconTransformation(origin = {100, -0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  end GenericFlow;

  model Outflow "Outflow from a stock"
    extends GenericFlow(redeclare SpecialFlowPort portA);
  end Outflow;

  connector FlowPort
    annotation(Icon(coordinateSystem(extent = {{-100, -100}, {100, 100}}, preserveAspectRatio = true, initialScale = 0.1, grid = {10, 10}), graphics = {Rectangle(visible = true, origin = {0, 5}, fillColor = {107, 255, 252}, fillPattern = FillPattern.Solid, extent = {{-50, -55}, {50, 55}})}));
  end FlowPort;

  connector SpecialFlowPort
    annotation(Icon(coordinateSystem(extent = {{-100, -100}, {100, 100}}, preserveAspectRatio = true, initialScale = 0.1, grid = {10, 10}), graphics = {Rectangle(visible = true, origin = {0, 5}, fillColor = {246, 114, 123}, fillPattern = FillPattern.Solid, extent = {{-50, -55}, {50, 55}})}));
  end SpecialFlowPort;
end ConnectorsTest;

That should indeed work and it does, at least in WSM 5.1. Perhaps you have an older version? 5.0 contained a lot of improvements regarding replaceable/redeclare.

Otto