What is it
Google My Business Product Editor changed its visual but also changed the way it orders the products.
How to
Just go to the “Product” tab of your Google My Business account (some business categories don’t have this feature).
In my opinion, visually it is cleaner with 2 quite self-explanatory buttons at the top: “Add Product” and “See it in Google”
Previous designs:
Previous Product Editor Design 
At the launch of the Product Editor
But they botched the flexibility by making difficult changing the products order, to change the order (position) of your products you need to… Well, I will let Google explain:
Recently edited products and categories display first in the Product Catalog. To showcase a product, make a minor update to the item to bring it to the top of the catalog.
Google My Business Article
Conclusion on this Google My Business Update
Why?! You cannot change the order of your products as you wish…
At least old listings are starting to get this feature as well.
If you have products, you “must” use this feature as Google is adding BOPIS (Buy Online Pickup in Store) features as per recent Google Shopping Update.
With all the new updates and future releases, Products are getting dedicated search results space, thus improving your chances of getting customers for your products.
Be Remarkable!
References:
https://support.google.com/business/answer/9124203
https://www.seroundtable.com/google-my-business-products-section-updated-29773.html