The Comcast tech support person came here and he told me that my router's firmware is updated automatically, also said Avast is what's causing the network issue..
He also said Avast would put viruses on my computer. I told him I had been using Avast for years and had never gotten a virus. He got on some website and Avast popped up and showed threat detected. He closed that so I didn't see what the threat detected was.