JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
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 did check your form and did not find any issue with that. You have set your form with to 1000 px and same is reflected in the preview as well. Please check the screenshot below:
Have you embedded your form in any webpage where you are having this issue with? Please share the webpage URL and we will take a look.
We will wait for your response.
and please advise is it cannot open by IE browser
It is advisable that you use Chrome or Firefox browser in editing your form. JotForm site might not behave properly on IE browsers especially the version that is lower that IE 11.
Do let us know if you need further assistance.