You are trying to make changes in settings of Netgear routers but they are not being saved.
Example : You click enable guest network. Check on the check box.
Clicked Apply, but after processioning The Guest Network option still
shows Turned off.
Solution :
The problem is not with the Netgear router. It is with your browser.
Most probably, you are using Google Chrome or IE 11 without
Compatibility Mode or Microsoft Edge Browser (For Windows 10 users)
Change your browser to Firefox or Internet Explorer, For IE 10, 11;
Use Compatibility Mode. Make the changes. It should work.