When configuring the admin server via the aphlict.custom.js file if you supply the key and crt file paths (and edit notification.servers to https) Phabricator is unable to connect.
Upon removing the key and crt, and changing notification.servers everything works great.
phabricator b2db1ec2ca21fee8461b6e399671bef5944cfa1e (Fri, Apr 15)
arcanist 737f5c0df976fe2b3178aac6ab7feb3d3621d99e (Sat, Apr 9)
phutil 7a184448aff55465476da0e13477b7e6f3446a14 (Thu, Apr 14)