EX6200 Wireless Extender in AP mode - Cannot turn off 5Ghz radio

Hello,

I have a EX6200/AC1200 extender running as an Access Point. When I log into the AP it gives me the NETGEAR genie interface with AC12000 WifI Access Point showing at the top of the screen, firmware V1.0.3.74_1.1.109. I'm not using any 5Ghz devices at home and I want to turn off the 5Ghz radio.

I go to Settings --> Wireless --> General and see the check boxes to Enable 2.4 Ghz and 5Ghz networks.

The problems is that even if I uncheck the Enable 5GHz wifi and then press SAVE, nothing happens. When I return to the same screen it stays checked and the network keeps broadcasting. The 5GHz light also stays on on the device it self.

I've had problems with different browser and the Netgear settings page not saving option, but I've used 4 different browser on my machine and also a couple of tablets, the same problem. I can uncheck the option, but it just keep staying checked.

Anybody have a similar problem or a solution for this?

Thanks,

Chris