Rate Quotes option is greyed out or disabled during shipment if from web orders
It is by system design that the rates from web order will be used so that the customer will pay and will match the exact freight charge when they placed that order on the website.
If you really would like to enable the Rate Quotes option in the Shipment form, you just have to change the "Customer PO" in the Sales Order. Information indicated in the Sales Order’s Customer PO field is where the Shipping Module determines if the order came from the website or not. For as long as there is no word "Web Order" in the Sales Order’s Customer PO, this will enable you to use the Rate Quotes option.
Go to Customer Module > Order > Find Order > Edit the Customer PO field to such as ‘Website Order’ instead of "Web Order"
All Connected Business Version