Initial property valuation wrong

I have a property I purchased several years ago. I provided paperwork as well public Zillow information that shows the purchase price. However, it is captured incorrectly in Stessa. I reached out and Stessa says I have no way to change this purchase price. It is not just a little bit off it is way off and really affecting my numbers. I don’t understand why this would be so hard to update especially when I have documentation for the purchase price.