I changed it with a brand new RSHTech 7-port USB hub, plus the black-monitor reboots continue. I am stumped right now, really beginning to suspect my UPS of spikes or momentary cutouts. in any case I feel the Sabrent is https://ihannagngw831924.actoblog.com/29275973/iogear-2-port-usb-2-0-automatic-printer-switch-for-dummies