As announced here: (Staging Hierarchy Changes)
the staging root was updated yesterday to new roots. We use the staging roots for testing in our dev environments as described on the staging environment page, putting those roots in our trust store.
The docs for the staging env (Staging Environment - Let's Encrypt - Free SSL/TLS Certificates) still have links to the old staging root. Where can the new root be found and could someone please update the page to have the correct root?