Cannot access some sites with last 2 Netgear routers I have installed using default settings with wi

I cannot access the site rail-logic.com with any of my devices over wired or wireless connection using the Nighthawk X10 or X6 router.

All settings are factory default.

If I bypass the router and connect directly to the cable modem, I can access the site with no problem.

If I use my wireless hot spot on my cell phone, I can also access the site with all my devices.

I read older post and tried changing the MTU setting with no improvement.

Appreciate any help, as the problem appears to be with the Netgear routers, and so far, I cannot find any settings to change that will allow me to access the site. I am impressed with the speed and the range of these routers.

My router is not in the list, so showing here. Nighthawk X10 AD7200 Smart WiFi Router.