Why do cart item properties disappear upon page refresh?

Technical Q&A
1

I am setting properties when adding to cart.

Ex:

var formdata=[
  "items":{
     id:123456,
     quantity:1
     properties:{'flag':true}
   }
];

Details I get from cart.js without refresh

[
    {
        "id": 32423423423423,
        "properties": {
            "flag": true
        },
        "quantity": 1,
        "variant_id": 42705234345345,
    }
]

The above items get added successfully to cart. After adding I again fetch the cart details and It has this properties value.But when I refresh the page cart items properties does not have any value.

Ex Currently I am getting this only when page is refreshed:

properties:{
   Ref: 0
}

What this properties is?

Why is this happening? If worked, will this properties be available on order create webhook? It only disappears when refreshed. Moreover main reason to add this properties is to receive this properties in order-create webhook to distinguish from normal order. If anyone having other alternative please suggest.

2

If anyone have suggestion. Do reply.