Most likely they are excluded from this destination. Go to Google Merchant Center > Products > Diagnostics and or check under Products > All Products > click on a product.
And see if you have excluded destination. And if so what value it has.
Also check the Google requirements here:https://support.google.com/merchants/answer/7159729
For Google Shopping actions, you will need to use a Google Express integration. Something like this app from CedCommerce works. It is a Google Shopping feature that requires more than your standard feed used in a shopping ad.