There are several options on the 'customize plugin' to check
On the Loans tab check that none of these options are selected
- Hide Ebooks
- Hide Magazines
- Hide titles already in library
And on General network tab, check that the following is selected.
- Include titles without downloadable formats.
If that doesn't fix the issue, can you check what it shows on the status line when you first open the plugin. It only displays for a few seconds, but should show you the number of loans and holds found.