Severe case of blocked highlights with Reagent III

Occasionally, on older roll film, I have found that Reagent III produces quite blocked up highlights. This is an old 120 roll of Kodak "special" film. That's all it says so I am not sure really what emulsion it is. If you compare it with another old roll, this one Verichrome Pan, from England posted here, you will see the familiar super white highlights = blocked, dense portions of the negative. Something not seen with the Efke, but seen a little with TMX, and not at all with the Pan F.