Not sure if this still an issue for you, but I was looking at this post when I was having a problem. I was having the exact same issue , had tried the exact same fixes (resets, port forwarding, heathchecks, hardwiring etc) , and even worked with ISP to see if there was anything wrong that they could detect. Nothing . In a last ditch effort , I replaced my router. Theres no explanation for this, but it fixed it .