Can you please be a bit more precise? What does "does not work" mean?

@xabbuh Apologies, I submitted the bug report before typing the info in. Have updated the description now.

My current work around is to add an event listener to strip the parts of the value that aren't expected by the TimeType's $format in the DateTimeToStringTransformer.

The array_slice here only give hours and minutes, as my input doesn't use the with_seconds option.

$builder->get('time')->addEventListener(
    FormEvents::PRE_SUBMIT,
    function (FormEvent $e) {
       $e->setData(
            implode(
                ':',
                array_slice(
                    explode(
                        ':',
                        explode(
                            '.',
                            $e->getData()
                        )[0]
                    ),
                    0,
                    2
                )
            )
        );
    }
);

@jackbentley Does that mean that Edge will always submit the value in the 20:11:00.000 format?

@xabbuh Correct. And it looks like the type is expecting hh:mm or hh:mm:ss if you have with_seconds.

@jackbentley Can you confirm that #36020 fixes this issue?