EX7300 can't access some pages

My internet service is through Sprectrum.  The router has no model name or number, but simply has Spectrum on the front.  It is connected to the cable box.  I properly installed my EX7300 where the Nighthawk app shows green from internet to router and green from router to EX7300.  When I connect my computer through the EX7300, my browser will allow opening some pages (e.g., Facebook) but not others (e.g., Amazon, Pinterest, etc.).  On my wife's work computer, it would not allow her to open Outlook or Microsoft Team.  I did the default setup of the EX7300 allowing it to use the same names for the 2.4 and 5ghz channels as the router.  I did the install twice thinking I may have something inappropriate the first time.  I even did a total system shutdown of the cable box, router, and all devices in the house.  Any suggestions out there.