Can you respond with what router you have? It helps me in troubleshooting. Also, when you ping do you see:
"Pinging google.com [2607:f8b0:4006:816::200e] with 32 bytes of data:"
The bold is the IPv6 address for google. That means your computer is resolving the website(domain) for a IP address so isn't a DNS issue.
What did you mean by "google websites"? Can you get to google.com? If so it is odd you can't ping it. If possible, try bypassing your router and connecting a device direct to the modem. If that doesn't work, I suggest contacting Cox and seeing if there is a problem in your area. You can either call or email them at cox.help@cox.com.