Updated 2 boxes to FreeNAS-11.2-U4.1 that were being monitored by TC. After updating and coming back online, TC showed the systems as offline (one actually showed offline, the other showed "connection refused"). Removed systems and re-entered as new systems, both units then showed again TC. To check connections after this, rebooted a system, after coming back online, TC showed the system. Appears to happen when updating.