Upgraded to a new Comcast Gateway, since then for 1 laptop only not seeing my 2.4 & 5 wifi network.

My son's laptop was connected to the same 2.4 and 5 wifi network that I had in the old gateway, after upgrading to the new gateway, every other device is connected to the network as I had kept the same name and pwd for the networks, but my son's laptop does not show these network in the list. Tried to reset the network setting on his laptop. Restarted the gateway. But no luck.