I have an airport extreme (4th gen, firmware version 7.6.4) wired to a netgear wnr1000 (for xfinity home) that is wired to the xfinity cable modem. Recently we have been experiencing extremely slow internet to no internet. All the routers were reset. With comcast also sending out a reset signal. Now, I am unable to join the network from any device. After multiple times of trying to join, with password reentered each time, the device will finally connect, but will have slow or intermittent internet. I also have an older express (1st gen) in basement, and a newer one (2nd gen) upstairs. Both running to extend the network. Any thoughts? Thanks.