@Ryan Thank you for the reply, I think I'll go the route of passthrough. Indeed, DHCP is still active on my AT&T router/modem. I seem to recall a document somewhere I saw when researching that...

It's long but I wanted to try to provide all the info out so hopefully it covers all bases for advice. Thank you in advance! Before moving I had the older AT&T mesh devices (AirTies 4970) that I...