My SG11224NA unmanaged switch seems to have issues with the LED port inidicators. Some of the ports show that a link is active (solid green light) even though there is nothing connected to the port except a cable which is not currently connected to any device. Other ports with cables that are not currently connected to a device have the LED off. If I remove the cable completely from the port, the LED will remain lit. Powering the switch off then on does not resolve the issue. Any suggestions?