Nighthawk ac1900 2.4 GHz wifi does not work but 5 GHz wifi does. Help please

So as title says my 2.4 GHz wifi is not showing in network list. The 2.4 lights on the router show it's working along with the control panel. I've tried a hard reset, changed wifi channel, and making sure the firmware was up to date. My internet provider( charter spectrum) said everything was fine on their end. I contacted Netgear and after trouble shooting they said something along the lines of my 2.4 signal was not being accepted but they could fix it if i purchased additional service since my expired. Any clue what type of troubleshooting they had planned? I ordered a new router/modem arris surfboard but before throwing in the towel wanted to see what you guys thought.