When trying to set the WAN port to negotiate at 2500 full duplex i cant not get an internet connection to my modem. I reset the modem and router after making the setting change and still lose internet

Just installed the ax11000 to work replace the CenturyLink provided actiontec a3000c. I put in the PPPoe information, setup vlan tagging, and I am connected. The issue is that the speedtest in the fir