Netgear Nighthawk 2350 v1 router set up question with intel AC9260 in notebooks

We are on Spectrum 500Mps down 20 up and for the most part everything is working great up to a few days ago, it seems like  we are getting a lot of DNS errors, can't find the site, sometimes windows - chrome goes through what looks like a trouble shooter and all of a sudden the site shows up... other times it does not.   

So I started to look at the Netgear router... I have unplugged my Modem and my router, let it sit a few moments and then plugged in the modem and waited until it was on line and stable, then, I'd plug in the Netgear router after a period of time seems like everything was coming up fine.  We do have quite a few attached devices but not everything is on and being used at the same time.... but, looking at the hardware I'd say a total of 24 devices are shown under attached devices most are wired with a handful of wireless 2.4 and 5ghz..

I decided to took at my settings and on my notebook the 9260 is 160mhz spec, but the Netgear does not have under 5g a 160 setting it is a 161 (I guess it's the channel)  setting tops.  I am showing I am getting the 1733  mode just fine.  

The DNS issue seems to come and go and all of a sudden we get a rash of it and then it goes away....   Is there others out here with this router (version 1)  and what channel are you using on 5g?   

This router is a bit older but I am waiting for United Communications to install the 1gb fiber before I change routers and that is going to be a few months down the road...    Any suggestions on my set up would be appreciated... and specifically with a similar set up. 

Thanks in advance