Magento 2 API not returning totals and items for checkout

I have a fully working Magento 2 website, now I want to use the API to create a mobile application so I am using rest api to checkout and place and order.

The problem in the shipping-information api which does not return order items and order totals so i can show them in the mobile app checkout page.
The flow I am using is like this:

1- get customer token using this api POST {{base_url}}/integration/customer/token
2- create quote for customer using this api POST {{base_url}}/carts/mine which return quote_id
3- add items to cart using this api POST {{base_url}}/carts/mine/items and the request body is

{
"cartItem":{
    "qty":1,
    "quoteId":"87846",
    "sku":"8681124614421"
}

}
and the response is

{
"item_id": 48508,
"sku": "8681124614421",
"qty": 2,
"name": "MUSK Eau De Parfum 100 ml",
"price": 644.07,
"product_type": "simple",
"quote_id": "87846"

}
4- calls estimate shipping method as follow POST {{base_url}}/carts/mine/estimate-shipping-methods
request body:

{
"address": {
    "street": [
        "dsfsdf"
    ],
    "city": "aaasdd",
    "region": "",
    "country_id": "TR",
    "postcode": "12345",
    "firstname": "aaa",
    "lastname": "bbb",
    "telephone": "3213510",
    "custom_attributes": [
        {
            "attribute_code": "student",
            "value": "",
            "label": " "
        }
    ],
    "save_in_address_book": 1
}

}

and response is:

[
{
    "carrier_code": "dhl",
    "method_code": null,
    "carrier_title": "DHL",
    "amount": 0,
    "base_amount": null,
    "available": false,
    "error_message": "This shipping method is currently unavailable. If you would like to ship using this shipping method, please contact us.",
    "price_excl_tax": 0,
    "price_incl_tax": 0
},
{
    "carrier_code": "flatrate",
    "method_code": "flatrate",
    "carrier_title": "Flat Rate",
    "method_title": "Fixed",
    "amount": 10,
    "base_amount": 10,
    "available": true,
    "error_message": "",
    "price_excl_tax": 8.47,
    "price_incl_tax": 10
}

]

5- finally where the problem is, i call POST {{base_url}}/carts/mine/shipping-information
with this request body:

{
"addressInformation": {
    "shipping_address": {
        "countryId": "TR",
        "region": "",
        "street": [
            "dsfsdf"
        ],
        "telephone": "3213510",
        "postcode": "12345",
        "city": "aaasdd",
        "firstname": "owais",
        "lastname": "hamouda",
        "saveInAddressBook": 1,
        "customAttributes": [
            {
                "attribute_code": "student",
                "value": "",
                "label": " "
            }
        ]
    },
    "billing_address": {
        "customerAddressId": "206",
        "countryId": "TR",
        "regionId": "43",
        "regionCode": null,
        "region": "Turkey",
        "customerId": "492",
        "street": [
            "160 1st St."
        ],
        "company": "Sawaftech",
        "telephone": "516-555-1111",
        "fax": null,
        "postcode": "11501",
        "city": "Mineola",
        "firstname": "Jane",
        "lastname": "Doe",
        "middlename": null,
        "prefix": null,
        "suffix": null,
        "vatId": null,
        "customAttributes": []
    },
    "shipping_method_code": "flatrate",
    "shipping_carrier_code": "flatrate",
    "extension_attributes": {}
}

}

and the response is:

{
"payment_methods": [
    {
        "code": "iyzipay",
        "title": "Kredi/Banka Kartı ile Ödeme"
    },
    {
        "code": "banktransfer",
        "title": "Banka Havalesi Ödeme"
    },
    {
        "code": "cashondelivery",
        "title": "Cash On Delivery"
    },
    {
        "code": "stripe_payments",
        "title": "Stripe"
    }
],
"totals": {
    "grand_total": 0,
    "weee_tax_applied_amount": null,
    "items": [],
    "total_segments": [
        {
            "code": "subtotal",
            "title": "Subtotal",
            "value": 0
        },
        {
            "code": "shipping",
            "title": "Shipping & Handling",
            "value": null
        },
        {
            "code": "tax",
            "title": "Tax",
            "value": 0,
            "extension_attributes": {
                "tax_grandtotal_details": []
            }
        },
        {
            "code": "grand_total",
            "title": "Grand Total",
            "value": null,
            "area": "footer"
        }
    ]
}

}

Here as you see the totals and sub totals, grand totals, items not returned from the api.
I also tried calling the collect-totals api, and totals api and didn’t get any value.
I am stuck on this issue for two weeks now, please help and advice what could be the problem, or how can i trace it or debug it if it is from an installed plugin for example.

Please note all the api calls i called it with header Authorization Bearer <customer token>
And note that the flow from the website is working correctly.