Why is my new router saying every site is unsafe?

Are you using and 3rd party security software?

One behavior of the router can cause issues with some security applications. For example, some applications may find it to be a security issue when a user tried to load a site like google and because the router is not fully set up, the router intercepts the page load and tries to redirect to router setup page. Even worse is an annoying behavior with newer Netgear firmware where instead of sticking with the router IP address, it will try to redirect to routerlogin.net The problem is that it will try that even if it is behind another router, and depending on how DNS is being handled on your PC, it could attempt to look for that URL on the WAN, and if security software is not specifically set up to be aware of scenarios like that, it could cause them to go crazy, thinking that there is something hijacking your WAN traffic (because the router technically is doing that to the requests, only thing is that it is a non-malicious use of that capability).

The easiest way to avoid this, if it there is an issue, head to the router's IP address and make sure it is fully set up so it doesn't try to intercept requests and direct you to the router setup page. If there is an issue with the setup, then it may be worth doing a factory reset of the router. Also make sure you are not behind  double NAT (Netgear router in router mode behind another router/ gateway device).