C3700 drops connection intermittently

Hello. I have had my modem since installing service almost 2 years ago. I get intermittent wi-fi signal dropped on a daily basis. We never knew how oftern thi was happening until we started to stream movies. Prior to we only used wi-fi or cellphone/tablet usage so we assumed it was our internet signal.

TWC/Spectrum has been out recently and noted they found no signal outtage emmiting from their servie and adviced my modem/router fimrware was outdated or not updaetd to the current version.

Since I have logged in and found my modem/router automatically updates the firmware. I have tried changing Channels on both networks (2.4/5) and still no changes.

I am also using a Netgear range extender WN3000RPv3, however notice the signal drops on both networks not just where i use the extender.

Please help!! :(