M/Monit 3.3, released on Friday unfortunately had a javascript bug in the status page which would hide one host in the host table. This is fixed as of Sunday 2. November 23:00 CET and does not affect new downloads of M/Monit 3.3 from http://mmonit.com/download/
If you have downloaded M/Monit 3.3 before Sunday, Nov 2, please save http://mmonit.com/dist/patch/3.3/status.js as mmonit-3.3/docroot/assets/status/status.js replacing the original status.js file which will fix the problem.
With apologises and best regards from the M/Monit team