@anas-akhtar
The code you are using to make these alterations were written by a member here; he specifically states that this will only work if you have also made it so that only one vendor can be allowed in the cart at one time.
I am sorry to say that we cannot support this custom code; it is not written by us nor do we have this type of function available in WC Vendors Pro without you doing significant custom codework that could have the potential to cause a conflict with other code within our Vendor Shipping module.
