JSON parsing of MySQL TEXT field

I have a MySQL table with a TEXT field with a JSON string and I would like to query this table filtering on field value inside JSON.

I tried first a SELECT All in this form:

SELECT *,CONVERT_FROM(config,'JSON') FROM MyTable

But, has I have for the same JSON field, different data types, I always got the error:
You tried to write a VarChar type when you are using a ValueWriter of type NullableBigIntWriterImpl
and similar (BigInt for example).

I tried changing the option store.json.all_text_mode and/or store.json.read_numbers_as_double but it seems the options are used only if reading from JSON files and not from CONVERT_FROM.