1 - You have insert API that is tested with postman and you receive acknowledgement and the inserted id. As understood by
YES
2 - You have API code that reads back correctly from the same connection/database/collection as mentioned by
MY GET READS CORRECT DATA ALREADY IN THE COLLECTION BUT NOT LIST DATA INSERTED BY THE POST ABOVE.
3 - What else is done between the time you test the API with postman and the time you verify that the data is saved?
One possible reason why documents are removed automatically would be the presence of a TTL index. But your sample document have no timestamp or date field, so it could not be the case.
NOTHING. I SEND POST WITH POSTMAN AND I SEND GET ALWAYS WITH POSTMAN. I’VE TRIED TO DO THE SAME INSERT DIRECTLY WITH COMPASS (WITHOUT ID, ONLY WITH KEY DESCTIPTION) AND THE DOCUMENT IS CORRECTLY SAVED ON COLLECTION.