C7000v2 Wifi connected without internet, then goes back to normal

Like I said on my last reply, we actually removed the coaxial splitter. The only thing different is the electrical power. I have it plugged into a 6-outlet surge protector now rather than a power strip. Could that be affecting it in anyway? That was going to be my next step: plug directly into normal wall outlet and see if that changes anything.

I will look at new coaxial cables. Any recommendations for my Netgear model?

I do have Xfinity. They bumped the 600mbps plan to 800mbps (which I didn't ask for) back . They started emailing me that my modem no longer is compatible with the new speed, but when they last notified me of that in Feb, I checked the Xfinity website, and my modem was listed as compatible. And the internet was working fine up until we disconnected this past weekend. Xfinity's website no longer lists it as a picture, but on the PDF of all compatible devices, it is listed for wired speeds up to 863 mbps. I refuse to rent from Xfinity, so I am hoping this is not them trying to back me into a corner and start giving them more $.

Currently at work now, so will regroup later with any more troubleshooting, if need be.