Hi. \Carbon_Fields\Field\Date_Field::set_value_from_input you try mode="multiple" date?

[KirStepankov]

This field don`t save, becouse in you code have logic a problem.
\DateTime::createFromFormat( $this->input_format_php, $input[ $this->get_name() ] );

DateTime::createFromFormat - accept only one date, but mode="multiple" give "01.07.2022, 08.07.2022, 07.07.2022, 14.07.2022"