Global Searching in FrameMarket/MarketPress

I have a FrameMarket/GridMarket/MarketPress install.

SiteA (global) has no products.
SiteB and SiteC (sub sites) have products.

The products from SiteB and SiteC appear in SiteA as expected.

However the search function at the global site does not find any products by either their name or from text in the descriptions, etc.

It works at the sub site level for products on that site

This makes the global site search fairly useless unless there is something I am missing here.

Any ideas on how to fix this or is it a bug?