JSON -> / ->> disparity; is this supposed to happen?

[A B]

DROP TABLE IF EXISTS `testtable`;
CREATE TABLE `testtable` (`field` TEXT);
INSERT INTO `testtable` VALUES ('{"order":1}'),('{"order":11}'),('{"order":2}');
SELECT MAX(field->'$.order'), MAX(field->>'$.order') FROM testtable;

the answer is "11, 2", which I don ot understand at all.