Intermittent internet outages.

I get several outings per week.  Most last just a few minutes.  Recently there have been some longer outings.  Every time I check the outage map it says everything is fine.

A couple weeks ago I bought a new router and modem.  Set them up, and still couldn't connect even though the outage map sad there were no problems.

I tried the old modem and I was able to connect.  As far as I could tell the new modem didn't do any better than the old one.  I returned the new modem, I'm currently using a Netgear CM500.

During the time of the trouble sometimes i could get to the internet with the old modem when connected to a hardwire even when the downstream light was red.  it seemed like the old modem would go in and out, but the new modem was always out.  It made me wonder if the new modem used tighter tolerances or something... like maybe the old modem was like, meh, good enough.

For about a week I was fine.  Then today, I couldn't connect for several hours.

I tried a hard wire directly from modem to a computer, didn't work.  All of the lights on the modem were good (on, green)

***:  This one seemed really weird - while connected hardwire I couldn't even get 192.168.100.1 to come up.  Am i correct in thinking that even if I don't have internet connectivity this should be available to me?

When the internet is working correctly i can get to 192.168.100.1 and it appears everything is in spec.  downstream power channels are all within -2 to -3.  upstream are all 54.  snr (i assume this is signal to noise ratio) is 42 something for all 16 locked channels.

During the time I couldn't connect, I went to xfinity support and ran the test to see if they can connect to my modem, it passed the test, said it could connect.

Are there other tests I could run?  

Thanks for any ideas!

[Edited:PII]