The form remembers my entries when I revisit the same link

Your method worked perfectly the first time, but the second time it remembered the info from my first test and populated the boxes with that. I tried the 2nd link again in an incogneto window and it worked fine. How does it work with caching and this method?

I think you have enabled the Save and Continue by Autofill in the form settings. Kindly check that.

https://www.jotform.com/help/227-How-to-Enable-Auto-Fill-on-Forms

Once this feature is enabled, it will save your data in the browser storage so you can come back to it later and submit.