Missing Shipping

Alex,
We are starting to receive orders without shipping charges applied. It is not all orders, and it is not restricted to one item. I created a test order and chose a shipping option, but on the payment screen only the item amount was shown, with no shipping added. In one order the ship cost line was missing, and in another the shipping was $0. Thoughts?

We had one of those also today with missing shipping and the customer chose Next Day Air. Fortunately, they are 1 day transit anyway

It normally depends on which carrier you're using.
Live pricing from UPS, FEDEX and USPS relies on external servers RTD queries via their API. So, if for whatever reason those servers are slow in replying, issues like this could happen.
I would vote for this as there's no consitency, which means it is not a "coding" problem, bur something related to specific network conditions.

I know this is not a solution but just an explanation, however I prefer to make clear what it can be. I can not see many ways to solve this, becuase to be sure it is "solved" I'd first need to be sure I can "cause" it... which I can't