Twitter widget working for top-level domain but not subdomain


Using the Twitter account @IAJGSConf, I created a widget to feature related tweets. It work from the top-level domain:

But not from the subdomain where it needs to show. (Can’t link to that page b/c it is password-protected.)

I can see that the JS is running without throwing any errors in the console, and the widget iframe is being rendered, but it is empty:

Any ideas why it won’t work from the subdomain? Thanks!