If the unit connects to something and operates as expected, then something in your network is suspect. From past experience, it is usually your firewall/router. I just recently changed my firewall and had all sorts of issues. Took several days to find out what ports to open and then had to turn off content filtering to get it to work. Try going into settings> network and run the diagnostic. It will tell you if it is a port issue. If it is not then may need to look at things like content filtering, stateful inspect, etc. Could try to turn off all firewall related settings to see if it will work. Also, if you have problems connecting with between TiVo devices within your network wirelessly, make sure AP isolation is off.
As a side note, I have read on somewhere on TCF or tivo.com that the xfinity wireless has issues with connectivity and TiVo devices. As far as I know, no one has done the above troubleshooting, but they turn off the wireless on the xfinity and they get a good AP and everything works.
"Delay is preferable to error" - Thomas Jefferson
"If I have seen further it is by standing on the shoulders of Giants" - Sir Isaac Newton