Hi, My name is ***** ***** certified computer professional with over 10 years experience. I will be glad to assist you with this. . I will need a little more info please>I am sorry to hear that you are having this issue. What type devices are you trying to connect to wifi?
What is the brand/model of your new modem? What is the operating system on the computer please?
okay, does the Arris have the wifi network name and security key listed on the label? or did you manually set that up?