No shipping options were found when mixing flat rate with regular rate products

Hey, I’m not sure if what I want to do is possible, but when a customer puts a flat rate (free shipping) item into the cart by it self (ie this product: https://jimsownsauce.com/product/pint-variety-two-pack) and checks out, everything works great. When they choose any other product by itself with a calculated rate (ie this one: https://jimsownsauce.com/product/jims-sauce-pint) and check out, again, works great. But if they add the flat rate one and the regular calculated rate one at the same time, they get the message “No shipping options were found” and cannot continue. Is there a way to make it so they can add both items and only pay shipping for the calculated one and not get the error message?

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