Shopify Orders Are Not Being Allowed to Process - Saying Shipping Isn't Available for that Province

[BettyF]

I hope someone can help me with this one! There are a bunch of products on my Shopify store from a variety of suppliers that are producing errors when customers try to purchase them.

The error says "Shipping isn't available for Ontario. Select a different address to continue". 

But the products can be shipped to Ontario, the suppliers have confirmed, and I have all the products set up on the Shipping settings.

Why is this happening? Andy why are some products with the same supplier selling and others get this reply all of a sudden?

[HCMANDS]

I have been having the same issue here in the states and I don't have multiple suppliers.  It has been going on for a few weeks now.  My customer will get a message "shipping isn't available for (insert State)".  But when the customer tries it again it will go through.  But honestly, I don't know how many potential customers I may have lost because of this if the customer didn't try again and moved on.