Calendar field generate block of submit

Hi, when a set a calendar field in a form submit action is not possibile and a message is shown: “One or more fields have an error. Please check and try again” . If I delete the calendar field the form is ok.

field is set as follow:

<label> Data (richiesto)

[date* data date-format:dd/mm/yy first-day:1 buttons]</label>

I tried with no date format, no other options..but nothing changed.

Plugin is up to date to lastest version.

Thank you

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