Ethernet 1 losing ip address from isp router

When it happens, have you tried pulling the WAN Ethernet cable and reconnecting it to see if that works? If it does, then perhaps there’s a similar issue using the default 2.5Ghz WAN port with your ISP’s router like I had with the Brume 2’s 2.5Ghz WAN port.

The problem I had with the 2.5Ghz WAN port on the Brume 2 was that it wouldn’t get an IP after a reboot which is the opposite of your situation. So I ended up swapping the 2.5Ghz WAN port around with the 1Ghz LAN port which fixed it.