Apple caches your AASA (Apple App Site Association) file periodically. This is used for signaling what site URLs should be Univeral Links to your iOS app.
You can view the contents of the cached site association file by inserting your
domain into the end of this URL --
https://app-site-association.cdn-apple.com/a/v1/[domain].
For instance, if my app's domain is www.my-app.com, then I'd pull up
https://app-site-association.cdn-apple.com/a/v1/www.my-app.com to see what is
cached.
Additionally, you can run your site association file through a validator by entering your domain into the form at AASA Validator.