I agree with Mr. Brungard. With a Kolsch, Im guessing, you needed to add chemicals to lower the pH - Lactic Acid, perhaps? If it was not well blended, or if you didn’t allow the grains enough time before testing, it may have caused an erroneous reading. I test my mash pH many times (3-5) and I mix the heck out of it before and after testing and before and after adding Acid. I believe the wort pH should be the same as the mash pH.