Internet constant disconnect, Arris Surfboard

A system restart has been done numerous times and it does not help. My internet quits working, tv and phone still work. I have an Arris SVG2482AC and have contacted their tech service and he confirmed all my gateway settings are in the parameters they should be. When it quits for about 10 minutes nothing but my LAN works (which is connected on the back of the surfboard) and the wi-fi lights are not on as they usually are. So is it Comcast or Arris issue? No splitters in the cables from the comcast tv spliter to the Arris.  The tv splitter is a comcast one they installed. Cable from outside to the splitter and 2 cables from there- 1 to the TV and 1 to the Arris.  Any ideas?