Ned help - WD My Net AC1300 Firewall

I own the WD My Net AC1300 and when I set up the firewall and I select deny it automatically goes straight back to allow. The website I am blocking is blocked but all the person has to do is unplug the router and plug it back in and the website is working again. Is there a way to keep it on “Deny”? I am about to chuck this router and buy a new one.

Also sorry if I posted this in the wrong section. New to the forum.

Welcome to the Community.

Have you performed a firmware update?

The latest firmware is 2013. I rolled it back to the previous version with the disc and now it seems to be working fine. So I think the firmware has something wrong with it.