As an administrator of Phabricator, there is a yellow notice in the top bar stating there is are Unresolved setup issues. That links me to https://phabricator.wikimedia.org/config/issue/ which says:
Unable to Connect to Notification Server
Phabricator is configured to use a notification server, but is not able to connect to it.
It tries to connect to a service on aphlict1001.eqiad.wmnet which is not available.