My cox gigablast internet has been going out for approx 10-15 secs every 15 mins then comes back. I restarted the modem as well as our devices and the issue has not been corrected. Any advice?

If it's a cox Panoramic modem, you should see 4 lights. Orange =no connection Green =see connection and White and solid = full connection. When you have the Blue light, that usually indicates the WPS button was pressed on the modem.