I’ve had a lot of issues with my internet since I moved into my apartment. Finally someone at Comcast told me my modem was incompatible with my speed so I bought an SBH8300. I’m trying to set up the modem and the lights are constantly flashing. The internet light blue and the wifi light green. They were both solid green like the manual says they should be for just a second and then started flashing again. 
 

I’ve tried contacting Xfinity but they’ve been useless and apparently arris doesn’t have a customer service line anyone can call. So I am here. Help me.