Arise's requirement is that you cannot use anything wireless. However this is for WiFi and does not include banning Internet Providers that use 5G connections etc. I was approved by Arise tech support to use a 5g wireless connection with T-Mobile internet and I am directly connected to the 5G modem.
Arise should clarify in their requirements as when Arise says wireless that is you can not have the computer's internet wireless which is via WI-Fi.
Arise's requirement is that there is a Ethernet cord running from your Internet provider's wireless modem and or router that will connect hard-wired to your computer.
So that actual modem or router does not have to be hard-wired to a phone jack or cable.
If your AT&T modem has an Ethernet port that you can connect your computer to, then you can keep the service and work with Arise