A couple things.
1. the ISP ultimately controls the firmware on modem's and combo devices. Its part of the docsis spec. Netgear can update the router and send it to the isp. But the ISP is the one that certifies it and updates it to devices. Sadly, they rarely do because it costs them $ to certify/test it. you can view your version versus what the current one is for your isp.
https://kb.netgear.com/000036375/What-s-the-latest-firmware-version-of-my-NETGEAR-cable-modem-or-mod...
2. Many times its not a firmware issue that causing problems. So a better description of whats actually going on that you think the firmware might fix would help.
3. I'd check your line. 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, bad/old/cheap connectors, or corroded connections. Replace them if you do.
If you can, simply connect the modem right where the coax comes into the home. This prevents wiring in the home from being the issue. And some ISP’s charge if the wiring issue is in the home. So this helps prevent this.
4. once thats done, if you still have issues, post back here with the details and a screen snip of the event log and the cable connections page.
