Hi I believe this problem started happening after macOS Sierra 10.12.6 updated on it's own but I'm not sure. What is happening is my internet connection works great and speedy for approximately an hour then slows down so much it won't even load a page. I then shut down my mac, start it back up, and it's back to working normally for about 45 minutes then the same slow down again. It is an older computer iMac (Mid 2010). -So far I've removed existing Wi-Fi preferences -Set a new network location -Reset SMC and reset PRAM / NVRAM -Factory reset router I have Comcast/Xfinity Wi-Fi. I've Posted this in another forum and no one could help. I'm getting very frustrated! I'm a novice with computers so any help would be greatly appreciated.