Apparently, the solution is to wait a week and see if the errors go away. 

Alex at Shopify helped me find a way to contact Facebook. I got a call from Miguel at 11pm. This appears to be a Facebook bug in receiving data via the Shopify API. There are 2 possibilities I'm seeing: 1) Wait. Do nothing. See if your products start...

We successfully set up our store in Facebook Commerce Manager using the Shopify datafeed. Phew! Bad News: All of our products are hidden due to the images. They meet all of FB's requirements and appear correctly (square) in the Details tab, just as i...