If you power off your router does the extra SSID go away also? Also do you have any extenders, repeaters, or such in your network?

I recommend that you get separate Modem and Router instead of the Gateway Combo model as they tend to have more issues and harder to debug if you have issues later. Many people have specific brands...

Just curious, what chip-set are you trying to use or avoid and what issues have you encountered with a specific chip-set?

Power down the modem, router, and connected devices, wait a few minutes and then power up the modem, then the router, then the devices. Many times that will correct things. If not, connect a PC via...

Also be sure your modem is up to date. The ISP sends signals on multiple channels (up and down). If you modem is old and only uses 4 channels down and your ISP supports 32 channels down it could...

Is your firmware up todate? Do you get these slow speeds with the device near the router? Also you can try reseting the router to factory specs and reenter your settings as that may help.