I'm not sure how long ago it happened at this point, but this issue started when I was hosting an online server for a game so I could play with a friend.
All of a sudden, I lost internet connection, and did everything I could to get it back. I even did a hard reset on my router. Eventually my wireless connection was restored, but every so often, I'd lose it again, and have to disconnect and reconnect from my network to get it back, so I resorted to using an Ethernet cable to hardwire my laptop to the router. Not internet problems since.
However, now I am unable to host game servers. People cannot connect to me, and attempting to forward my ports does not work. (I even configured my router's settings again)
In my device manager, it is showing my WAN (which I assume is related to the router) as offline.
What brand of router is this? Is this a home router? Have you webbed in to on the standard 192.168.1.1 address? Sounds like the router is not pulling IP address from the ISP and it sounds like it is not the ISP's fault you laptop works fine.