fix-jet-engine-forms-import.php

<?php

add_action( 'import_post_meta', function( $post_id, $key, $value ) {

	$slashit = array( '_form_data', '_notifications_data' );

	if ( in_array( $key, $slashit ) && '[]' !== $value ) {
		delete_post_meta( $post_id, $key );
		update_post_meta( $post_id, $key, $value );
	}

}, 10, 3 );