What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
If the old image is the one showing on Facebook, it's most likely be due to the sharer cache of facebook which is causing the issue.
You can check out these pages for more information on how to clear facebook's sharer cache in order for the new image to load when the link gets shared on their platform:
If you have questions, please let us know.