At least one of my items don't get tax/shipping information communicated with Google Shopping. ebid support is contacted and they fixed shipping information but tax is still not submitted. They're working on it so probably better holding off contacting them if you have the same problem.

What's the problem? When your listing doesn't have tax and/or shipping information on Google Shopping, total price can't be calculated so if a buyer sorts the listings based on total price, your listing sinks to the bottom of the list even if your total price is lower than others.