Hi Pepe,
Thank you so much for following up with me. I just went through all of your suggestions and also had my status message posted here – and then I figured it out!!
The answer was in the first few paragraphs of the document on “shipping zones” that you linked.
For some reason, the fine art print service that I use (the dropshipping agents) imported a “Free Shipping” zone, and it was first in the hierarchy. I had disabled it (while leaving it at the top of the zones), but because it overlapped with EU, Germany, US, etc., it seems to have caused a conflict which returned the “no shipping options found” error message.
I have moved it to the bottom of the hierarchy for now and will delete it once I’ve added Free Shipping to each of the zones, as a triggerable option.
Thank you so much for pointing me in the right direction. You have been so helpful and efficient here!
Warm regards,
Wes