I have a form in a modal, the user has to complete the form (otherwise validation will display the required fields error messages), then click the submit input type, it does
I had the same issue and resolved it by adding the following to my validate:
$("#myform").validate({ onfocusout: false });
onfocusout will remove the focus from your form fields and submit button will work on the first click.
onfocusout
See more at https://jqueryvalidation.org/validate/