Storing \stdClass object in json_document

[erop]

I have a really non-typed JSON input that successfully decoded into stdClass object with json_decode($json) But after persisting the whole entity in Postgres I can only see {"#type": "stdClass"} without any actual data in JSONB column. If I add $assoc = true parameter to json_decode, it successfully saves an array. That's OK for storing and retrieving data. But using arrows instead of square brackets could be more fun. Moreover I found out that on hitting https://github.com/dunglas/doctrine-json-odm/blob/master/src/Serializer.php#L23 $normalizedData local variable is an empty array while $data is still "well-formed" stdClass with huge amount of properties. Is it feature or bug?