The other collection pages are fine. The settings are the same and products do match the conditions required. I cleared the collection cache and that didn't resolve the issue, so I actually rebuilt the collection: https://fringe-co.com/collections/t-shirt
However, the rebuilt collection does not display the items either. This client does use the app Product Filter & Search, which we only use for the T-shirts Collection, so there's a chance the app is the issue, but it's worked in the past (for about a year). The Standard filter trees are working however. When I turn off the Custom filter tree (for the T-shirts Collection) that doesn't fix the blank collection page issue.
It's only the T-shirts Collection page that is blank in the product loading/display section. The sidebar still loads, with the thumb.
Anyone have a similar issue? You see the products flash for a split second before it goes blank.
I just debugged your code and I see that there is an app with the name of bc-sf-filter that is making your collection disappear. It's probably an app to filter your collections.
Either uninstall it or contact their support to have your issue fixed.