So I have an issue with a site with the following behavior

1. Information is submitted to a form (search.aspx), site is located in our DMZ
2. Upon Button Click the code behind, which I have no access to, queries a sql database internal to network
3. I see the request pass the firewall and hit the database successfully
4. Data is displayed correctly
5. User click print and a letter is supposed to be populated with the data found by the search.aspx page.
6. letter.aspx loads but all fields are blank.

This started around the beginning of July

I have rolled back updates, restore to known good dates

I have made not changes to this site since April of 2016

I have not changed the database other than data entry since November of 2017.

I am not a web guy, and since I don't have access to the codebehind I am at a loss, hoping someone can point me in the right direction as I'm not even sure what terminology to use to begin to search this issue.

Thanks!