Block Sites not Blocking Sites, GIves 404 Forbidden Error when I try to Apply

Hi, I'm having a bit of a hard time trying to block a site using my new router.

When I use the Block Sites function under Security while logged  into my router using any browser on my Windows 10 or Linux PC and I enter https://youtube.com for example I can add keyword to the list but when I try to apply I get a '404 Forbidden" error instead of a blocked site. I tried using just www.youtube.com which lets me apply the change to keyword list but it doesnt actually block youtube. While using Windows 10 I have tried on Chrome, Firefox, Microsoft Edge, and Microsoft Edge Beta and get same 404 Forbidden error everytime. While on Linux I have tried Chromium Browser, and Firefox which gave me same results.     

I do not see any option anywhere in the Nighthawk app to block sites, only a way to pause devices.  I do not see the Parental Controls option in Netgear Genie software (dont get me started on this)  like the linked video shows when you click Parental Controls. I also do not see any way to control access/parental controls after logging into OpenDNS either.  

My router model number is: R6350 but it is not in the dropdown above.  

Firmware Version: v1.1.0.78_1.0.1 

Thanks in advance for your help.