Problem with shipping cost if different sites use different methods

I have a main site and 3 vendor sites on a MarketPress multisite using GridMarket child theme.

The ONLY way that the shipping costs will display correctly is if all of the sites pick the same method for their shipping. I've tried every variation and that is the consistent end result.

I want to have one site using one method (Table Rate), 2 sites using (Calculated Options) and the main site using No Shipping because it doesn't have any products.

Is this possible or do all of the sites have to pick the same method?

Thanks for your help.