AC1750 6400v2 Dual Band WiFi Router - unreliable 2.4Ghz connection

I've been using the Netgear AC1750 6400v2 dual band wifi router at home for about a year without issue. But recently, I cannot access the internet over the 2.4Ghz band. I have no issues connecting to the router over that band and staying connected from multiple devices, but those devices then have unreliable internet access. This is true whether I am immediately next to the router, farther away in the house, or trying to connect via Netgear wifi extenders. This is true for all 4 members of my family accessing the internet from their multiple devices. Total device count peaks at 14 devices.

 

I have no issues connecting to the 5Ghz band or to the internet through the 5Ghz band.

 

I've reviewed multiple posts about other wifi products, and have tried rebooting the cable model (not from Netgear), rebooting the wifi router, and resetting the wifi router to factory settings. None of that has worked.

 

I probably wouldn't care much because most of our devices can connect over 5Ghz band; however, we now own 3 security cameras that only connect over the 2.4Ghz network. And while that was working for several months, the poor connection now prevents them from working effectively.

 

Suggestions?

 

Thanks.