@RachH 

Hello, what if you connect the ADSL modem filter into the Ethernet port of your computer directly, do you have internet access? If not, I'm afraid there is some special settings on the ADSL modem, you may try the below steps to clone your old Linksys router's MAC address to the A7, then check again:

1. Connect your ISP ADSL modem filter in your old Linksys router which was working fine. Login in Linksys router and there you will find summary or status page where you will have some info about your LAN, WAN IP address, MAC address etc.

2. For MAC address, you will find 2: one in LAN info MAC address and the other in ISP info MAC address. Please copy the MAC address that you see in the internet status group and note it down.

3. Once done connect the new A7 router with your ISP and perform quick setup. Now go to Advanced tab on A7 and click internet settings. There you will find use custom MAC address and insert the MAC address that you noted of the old Linksys router, perform save then confirm.