gllCAX80

I have a Nighthawk model CAX80 cable modem and router. Purchased from Best Buy two weeks ago. Everything seems to be working correctly except the "DOWNSTREAM" light on my modem is flashing white. I've reset this numerous times and after it reboots it stays solid white for about one or two days then starts blinking white. Everything seems to be working correctly. Is it supposed to be blinking white? The instruction sheet says that the modem/router is scanning for a downstream channel. I've waited several days to see if the blinking light would stop but it doesn't. How do I correct this and is this normal. Any insight would be appreciated. I paid a lot for the modem/router. I'm hoping it's not defective.