Fields hidden but form still submitted by users

We created a form to allow people to request a book and gave them the option to make a donation to cover shipping costs, etc.

After we ran low on books, I made almost all of the fields hidden and left only a message saying the book is no longer available and to contact the publisher for more information.

The strange thing is, after hiding all the fields, we received a form submission this morning. I don't know how to explain that this person was able to submit a form after the fields were hidden. Any help would be appreciated.

Hi,

I have checked your form, and I can't seem to access the submit button through the form's direct link. However, as I have further verified it on build mode, the submit button is not hidden by default as well as the Offering amount and all the fields on the 2nd page are not hidden:

But I'm not sure how the user advanced to the 2nd page when the page break on the first page is hidden. I would also recommend hiding the fields on page 2 will surely prevent users from submitting the form. If the form is embedded on a webpage, may we ask for the URL where it is located to investigate it further from our end?

Looking forward to your response. Thank you.

Thanks for your response. Actually I wanted to hide the Offering amount
and Submit fields but it seems that there is no option to hide them. Could
you please verify whether this is indeed the case? That is why I moved
them onto a second page and hid the "next" button as a workaround.
The form is not embedded on a web page. We sent people directly to the
form.
Thanks for your help.
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I believe you are referring to this last submission on Jan 31, 2021:

From your form I can see that all fields are hidden and there is no possibility of the person from filling the form:

Did you hide all fields on the form after you got this submission?

If not, I think this could have been a form cache issue. I have cleared that on your account.

I hid all the fields before that submission which is why I was confused. I
can't think of anything other than it could have been a form cache issue.
Is there a way for me to clear the cache?
...

Yes, you can also clear the form cache from your account.

Please check this related guide for reference: https://www.jotform.com/help/229-how-to-clear-your-form-cache

Do check and let us know if you have any further queries.

Thanks very much.
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