Usually, a fast drying time is an indicator of high porosity hair. Therefore, I wonder if you had any products/ oils or conditioners on the strands you tested? It can help test the strands after a wash with a sulfate shampoo (before conditioner or any other products are applied) if you are getting conflicting results! Also, I don't know whether you did this already, but try testing a few different strands, too, perhaps from different areas of your head, if you can!