I am trying to redirect a URL to a third level domain page under dotCERN, and while the Drupal redirect tool seems to be working, the redirection is not actually happening.
You already have a node with the URL donate and this creates a conflict.
Try to change the alias of that node to something else first, then delete the redirection from the node’s page that the system will create automatically from the old alias (donate).
After that check that the donate URL takes you to Page not found and then you are ready to place the redirection.