Remote Management can't be turned off
Using V188.8.131.52, I was able to turn on remote management. I was unable to turn it off. After working with Netgear for some time, the only solution they came up with was to reset the router and rebuild my configuration.
I did not try restoring a saved configuration. That might have worked, but I was just following orders.
In any case, this is a pain in the neck.