Mongoose/Express population issue

I implemented your code and Schemas, It's work for me, if you stored data correctly in the database, every things will be ok...

note :

please use find({}) instead of findOne() if data is not displayed again for postedby key, Other issues need to be addressed like mongoose version and ..., because your code and schemas is correct

it's result for me with find({}):

[    {        "postedby": [            {                "records": [                    "5ff6bc0bd9e7437184b83f76",                    "5ff6bc23d9e7437184b83f78",                    "5ff6bc85f1045a4f102bc0cd",                    "5ff6bca1f1045a4f102bc0ce",                    "5ff6bca5f1045a4f102bc0cf",                    "5ff6bcb3f1045a4f102bc0d0",                    "5ff6bcc7f1045a4f102bc0d1"                ],                "_id": "5ff6b81df463322abc7406ec",                "Date": "2021-01-07T07:28:15.654Z",                "email": "a@test.com",                "password": "$2a$12$wJVDysQxbjuRve.hYn/lbO0rskhwj6y8lwDuEWpCwHeNT/V2mybs.",                "__v": 7            }        ],        "Likes": 1,        "Date": "2021-01-07T07:47:11.610Z",        "_id": "5ff6bca1f1045a4f102bc0ce",        "Title": "farsi",        "Author": "javid1",        "ISBN": "1",        "Review": "1",        "SelectedFile": "1",        "__v": 0    },    {        "postedby": [            {                "records": [                    "5ff6bc0bd9e7437184b83f76",                    "5ff6bc23d9e7437184b83f78",                    "5ff6bc85f1045a4f102bc0cd",                    "5ff6bca1f1045a4f102bc0ce",                    "5ff6bca5f1045a4f102bc0cf",                    "5ff6bcb3f1045a4f102bc0d0",                    "5ff6bcc7f1045a4f102bc0d1"                ],                "_id": "5ff6b81df463322abc7406ec",                "Date": "2021-01-07T07:28:15.654Z",                "email": "a@test.com",                "password": "$2a$12$wJVDysQxbjuRve.hYn/lbO0rskhwj6y8lwDuEWpCwHeNT/V2mybs.",                "__v": 7            }        ],        "Likes": 1,        "Date": "2021-01-07T07:47:11.610Z",        "_id": "5ff6bca5f1045a4f102bc0cf",        "Title": "farsi",        "Author": "javid1",        "ISBN": "1",        "Review": "1",        "SelectedFile": "1",        "__v": 0    },    {        "postedby": [            {                "records": [                    "5ff6bc0bd9e7437184b83f76",                    "5ff6bc23d9e7437184b83f78",                    "5ff6bc85f1045a4f102bc0cd",                    "5ff6bca1f1045a4f102bc0ce",                    "5ff6bca5f1045a4f102bc0cf",                    "5ff6bcb3f1045a4f102bc0d0",                    "5ff6bcc7f1045a4f102bc0d1"                ],                "_id": "5ff6b81df463322abc7406ec",                "Date": "2021-01-07T07:28:15.654Z",                "email": "a@test.com",                "password": "$2a$12$wJVDysQxbjuRve.hYn/lbO0rskhwj6y8lwDuEWpCwHeNT/V2mybs.",                "__v": 7            }        ],        "Likes": 1,        "Date": "2021-01-07T07:47:11.610Z",        "_id": "5ff6bcb3f1045a4f102bc0d0",        "Title": "riyazi",        "Author": "javid1",        "ISBN": "1",        "Review": "1",        "SelectedFile": "1",        "__v": 0    },    {        "postedby": [            {                "records": [                    "5ff6bc0bd9e7437184b83f76",                    "5ff6bc23d9e7437184b83f78",                    "5ff6bc85f1045a4f102bc0cd",                    "5ff6bca1f1045a4f102bc0ce",                    "5ff6bca5f1045a4f102bc0cf",                    "5ff6bcb3f1045a4f102bc0d0",                    "5ff6bcc7f1045a4f102bc0d1"                ],                "_id": "5ff6b81df463322abc7406ec",                "Date": "2021-01-07T07:28:15.654Z",                "email": "a@test.com",                "password": "$2a$12$wJVDysQxbjuRve.hYn/lbO0rskhwj6y8lwDuEWpCwHeNT/V2mybs.",                "__v": 7            }        ],        "Likes": 1,        "Date": "2021-01-07T07:47:11.610Z",        "_id": "5ff6bcc7f1045a4f102bc0d1",        "Title": "zaban",        "Author": "javid1",        "ISBN": "1",        "Review": "1",        "SelectedFile": "1",        "__v": 0    },    {        "postedby": [            {                "records": [                    "5ff6c275964d062f045e93d3",                    "5ff6c283964d062f045e93d5"                ],                "_id": "5ff6c253964d062f045e93d2",                "Date": "2021-01-07T08:01:21.499Z",                "email": "b@test.com",                "password": "$2a$12$jmHUrTSPwjaVd0VEIpsGauExHNSukHRyWWiJt4UlEgeWLBo8GPDH.",                "__v": 2            }        ],        "Likes": 1,        "Date": "2021-01-07T08:01:21.990Z",        "_id": "5ff6c275964d062f045e93d3",        "Title": "zaban",        "Author": "javid1",        "ISBN": "1",        "Review": "1",        "SelectedFile": "1",        "__v": 0    },    {        "postedby": [            {                "records": [                    "5ff6c275964d062f045e93d3",                    "5ff6c283964d062f045e93d5"                ],                "_id": "5ff6c253964d062f045e93d2",                "Date": "2021-01-07T08:01:21.499Z",                "email": "b@test.com",                "password": "$2a$12$jmHUrTSPwjaVd0VEIpsGauExHNSukHRyWWiJt4UlEgeWLBo8GPDH.",                "__v": 2            }        ],        "Likes": 1,        "Date": "2021-01-07T08:01:21.990Z",        "_id": "5ff6c283964d062f045e93d5",        "Title": "tttt",        "Author": "javid1",        "ISBN": "1",        "Review": "1",        "SelectedFile": "1",        "__v": 0    }]