Suddenly getting a "date must not be in the past" error message on a date of birth field

This form has been working fine for quite awhile but all of a sudden the date of birth field is generating a "date must not be in the past" error message that disallows submission of the order.

 

For obvious reasons a date of birth field is a date in the past by its' very nature.

And, just to have it said, I have not done any recent work on my forms.

 

Can you please tell me;

1) why this is happening when it has never been a problem before?

2) how to fix it?

I've cloned your JotForm to my account to check the issue. I notice that the option "Disable Past Dates" is selected as Yes in the properties of Date of Birth field which is causing the issue.

Please change the option to No so that it should accept past dates.

Hope this information helps. Let us know if you need any further assistance. We will be happy to help.

I will go in now and make the suggested change but I saw that when I
looked at the form this morning and I didn't change it because I want to
know why it is suddenly showing this message.
As I mentioned, my forms haven't been touched by me in months.
Thank you
...

Do you have any sub-account users shared with your JotForms to edit? I'm not sure why it happened at the moment if the changes are not made by any sub-account user. I've checked with some of my previous forms to see if there is any update for the field. However they seem to work normally. Please make the change to the field and see if the issue occurs again so that we can report it to our backend team. 

Thank you!