Which, as I said, is unrelated to wearing robes or not. Any body slot item, be it Full Plate or Robes, has it's Dodge cap directly from it's Max Dex Bonus. Robes have no Max Dex Bonus, therefore, robes have no Dodge cap. I'm talking about equipment. The fact that characters have an overall Dodge cap is not relevant.
If you actually have any evidence of your claim that robes have some kind of built-in Dodge cap, I'd still like to see it.