Credit was dinged by unpaid utility bill

[Dan Bass]

Hello BP! Within the last year, I purchased several properties and I missed one utility bill that went into collections. Since this happened I have paid it off and thought all was well. I went to apply for another mortgage and my bank said my mid score was too low! When I check my credit card apps, 2 of my scores are over the 720 minimum. Do banks use a different algorithm than credit cards since my scores were different than what the bank has said? I went to a mortgage broker friend and he pulled the same scores as my bank and he said they were too low as well, all the while my credit card scores are almost at 800 or above.

Thank you!