I've added Facebook as a sales channel and also the Facebook Marketing app on a store. The Facebook sales channel has successfully connected with the appropriate Facebook Business Page, and the feed of products has made its way and the products appear properly in the Shop section.
Note: I haven't used Facebook Marketing to create an ad campaign.
However, I have just attempted to create Facebook Business Ad (actually a split A/B test). Upon visiting the Catalog Manager, I notice that there are 2 catalogs.
So my question is when you create Dynamic Product Ads does it automatically create a separate catalog for use?
When you create a Dynamic Product Ads campaign.. it does not make your FB catalog. The two catalogs you have are based on the sales channel (the one owned by SHopify) and the Facebook Marketing app. The only other way you would have a FB catalog would be if it was based off your pixel. It's usually best to just have one catalog and build your DPA campagns and FB page shop off that. Making managing it easier as you grow the business.