The objects.inv file that can be found at https://googleapis.dev/python/storage/latest/objects.inv links to the wrong location. For example, google.cloud.storage.client.Client ought to link to:

https://cloud.google.com/python/docs/reference/storage/latest/google.cloud.storage.client.Client

But it actually links to:

https://cloud.google.com/python/docs/reference/storage/latest/index.html#google.cloud.storage.client.Client

Inspecting the manifest by running:

python -m sphinx.ext.intersphinx https://googleapis.dev/python/storage/latest/objects.inv

We get the following:

py:class
 google.cloud.storage.client.Client: storage/client.html#google.cloud.storage.client.Client

Based on how the site behaves my guess is that because storage/client.html is an unknown page, that's getting redirected to index.html while preserving the #google.cloud.storage.client.Client.