I've run into an issue with automatic collections. My existing collections all work, but I'm unable to make new ones. Now when I make automatic collections (based on only 1 tag), none of the products appear on my site preview.
I've tried to isolate the issue, but am unsuccessful so far. Here is where I've gotten: I can add products with the default Shopify collection editor. When I input a simple tag rule (in this example, tag="mens") the appropriate products appear in the back-end.
However, None of the products fully load when I preview the site. Instead, they display for a fraction of a second:
Then, the page changes. It says that the collection is empty, even though products were just visible.
The issue doesn't seem to be theme-based, because it occurs in unedited free themes (where no one has messed with the code). And again, my pre-existing collections still display correctly on the preview site.