Does my bank use a different credit score than agencies report

[Jens Nielsen]

I have excellent credit > 800 when I get my score from the various credit agencies. I also get the same score on CreditKarma and on my credit card website.

However, I do have one closed collection account om report for $95. It was a medical bill that was sent to my old address after a hospital stay. I payed the bill when I finally found out it had been sent to collection. This account does not show up on CreditKarma.

Then I applied for a mortgage with a local bank, and they inform me that my credit score is ~680 to 700, thus resulting in higher interest rates.

From what I read I understand that collection accounts under $100 should be ignored on my score with the FICO08 calculations. I guess my question is; does mortgage lender user a different scoring method? Should I try a different lender to see if they offer a better rate?

Thanks for any insight.