Nighthawk X6S AC3000 Tri Band WiFi Router ...internet keeps timing out

Hi, I'm a newbie here, so be kind! 😉

OK, after two weeks of thinking it was my PC, I think I've narrowed down the problem to my router. Here are the facts:

1) just realized today that my husband and I are having the exact same problem

2) internet service seems fine

3) in a nutshell, it doesn't matter which site we try to access on our PCs and phones, there is a lag. So much so that we invariably get the 'This site can't be reached' page (see attached). We can hit reload several times and it does ultimately come up.

4)we've tried different browsers, same thing.

So, by process of elimination, we've come to the router. Any suggestions? I'm really fairly ignorant about it, my son set it up and now lives across the country.  

Oh, and I did do a quick check online and discovered that Orbi has 'performance issues' and was last update June 9, which may have been about the time this all started. But, I don't know what Orbi does or how to fix the performance issues..