Devices going offline in Endpoint Manager

Hi, I’m having a major issue. It seems like every few days I am having more and more devices going offline in endpoint manager even though the devices are online. One common theme I’ve noticed is if I right click on the Itarian Communications Icon next to the clock and click about, the server is empty. This has happened to about 15 of my servers/desktops now. Anyone have any clues as to what this bizarre behavior is? Restarting the service or computer gets the device to come back online but only for a short while.