Not working on Woocommerce checkout page

I think this plugin is a really great idea. It saves me of a lot of time searching through code.

Unfortunately it is not working on the page where I need it most: the Woocommerce check-out page. The page won’t load completely (shows a rotating icon in the cart items section and the comments section). As a result I can’t click the buttons on this page to deliberately cause errors. (As some errors are displayed in unexpected places I want to know what hooks are used.)
This seems to be Javascript that can’t be completed. But I only have some basic knowledge about building websites (PHP, CSS, JS), so I’m not sure.

Tested with OceanWP theme (child and original) and Twenty Twenty-One theme with the same result.

BTW: I’m building the website locally, so I can’t share a link.

Any help to get this working is really appreciated.