Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly. Be sure there are no coax cable line splitters in the between the modem and ISP service box. Be sure your using good quality RG6 coax cable up to the modem. Start with removing any amplifiers, signal attenuators, or splitters from the coax. From there check the line for kinks, damage, moisture in the line. Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do. Be sure to power OFF the modem for 1 minute then back ON. https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod... https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
