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.
I took a look at the Form Designer and did not have any issues with it. I even cloned your jotform to make sure that the issue is not with the jotform itself, but I was able to save the changes as well.
Would you please mind using FireFox to see if it works for you?
If it does the issue would be caused by your browser cache and could be resolved by following the next steps: 15 Ways to Clear Your Browser's Cache - wikiHow
Do let us know if you continue experiencing the same issue with FireFox as well.