My ISP just installed my 1gb fiber internet connection using an AdTran modem model #1287405F1
Previously with my old connection and modem I used a Netgear AC1750 Smart WiFi Router model #R6400
But now when I'm connected to the AdTran modem through the router I can no longer sign in to the router homepage. It just redirects to Netgear's website no matter what method I use. However if I disconnect from the modem and ONLY plug into the router, I can log in to it normally. Is there some compatibility issue here?