Having issues with multiple POD apps during checkout, any solutions?

[MamiSays]

Hello all,

I'm very new to this and not sure how to find the answer to my question.

I'm using Printful and Printfy. I went in to my site, Mamisays.com, as a customer and added one product from each POD supplier to my cart. When I got to shipping, I got a message that shipping was unavailable to my address. However, when I tried checking out each product individually it was fine. What do I need to fix?

Thank you!