All lights are on the modem and it looks just like normal when it stops working. When looking at the router page, it is not getting an IP address from the modem. The ASUS router gave the error "your ISPs DHCP service isn't functioning properly" or something to that effect, the edgerouter just shows as no data.
Plugging in directly doesn't work either. Resetting the modem from the Cox webpage seems to work better than just cycling power, and that seems like the only way to fix the issue when it goes out. Went out around 11pm last night, got it working this morning with a reset, and it stopped working again a few hours later.