Magento 2.1.2. I have set up a test installation, with four sites, each with one Store and View (and corresponding root Category). I have previously successfully added products, set their categories, and they appear on the front end where expected.
But now I notice that as I add a new Product it acquires a Store View setting that's not the one I want, and there's no way to change it. After first save, when I edit the Product, there's a Store View switcher control at the top left, but it only offers the store view that the product is already configured for, and not the other three.
How is this supposed to work? Why is there no way to select a Store View scope when you first create the product? (As noted here: http://docs.magento.com/m2/ce/user_guide/catalog/product-workspace.html). If you have to go back to edit the scope, then why doesn't it offer other scopes? Have I hit a bug?
Best Answer
After quite a bit of wild-goose-chasing, I've discovered the root of the enigmatic behavior.
Before using the New Product function and page, you must first visit the configuration page for the Site that you want the product to pertain to.
Stores > All Stores > [select Web Site] >
On that config page, check the "Set as Default" button.
Now start the Add New Product process.
Way down the Product configuration page there's a setting for "Product in Websites", on which you can set which Websites the product is available on. (And not to be confused with the Categories setting and mechanism.)
It looks like the "Set as Default" (Website) preselects that Website in the "Product in Websites" settings.
You can use "Product in Websites" to add one or more additional sites. After saving that setting, the product config page will then display a Scope control at top left, including scopes for those sites.
More at: https://community.magento.com/t5/Technical-Issues/New-Product-Site-Scope-and-quot-Default-Site-quot-issues-bugs/m-p/52595#M1518