Checking if field is empty not working

Hello! I’m trying to check if a field is empty to add in a custom error message.

Here is the strange part and I don’t know what I’m missing. For a test, I did a simple form.

<label> Your name
    [text* your-name] </label>

<label> Your message (optional)
    [textarea* your-message] </label>

[submit "Submit"]

If I check if your-name field is NOT empty, this code works great.

add_filter('wpcf7_validate_text*', 'custom_text_validation_filter', 20, 2);

function custom_text_validation_filter($result, $tag) {
	
	if ('your-name' == $tag->name) {
		$field_name = isset( $_POST['your-name'] ) ? trim( $_POST['your-name'] ) : '';
		
		if ($field_name !== '') {
			 $result->invalidate( $tag, "Are you sure this is the correct name?" );
		}
	}

    return $result;
}

As you see, I’m checking if field_name is NOT empty.
BUT, if I change that to check if the field IS empty, the form just displays the generic “Please fill out this field text”.

add_filter('wpcf7_validate_text*', 'custom_text_validation_filter', 20, 2);

function custom_text_validation_filter($result, $tag) {
	
	if ('your-name' == $tag->name) {
		$field_name = isset( $_POST['your-name'] ) ? trim( $_POST['your-name'] ) : '';
		
		if ($field_name == '') {
			 $result->invalidate( $tag, "Are you sure this is the correct name?" );
		}
	}

    return $result;
}

I’m unsure why checking if its not empty is working correctly but changing it to check if it IS empty is not working.

Anyone see what I could be doing wrong?