The 360 was easier when it came to setup. Don't ask why, but the X1 seems to need setup to be spot on.
Honestly, get Netgear on the phone. Get them to set up your router. Give the X1 PF, if you still use the 360 --> place this in the DMZ.
Remember to add port 3076 for the X1.
Upnp is good. PF best for gameplay.
If your router has had a firmware update recently it may need a factory reset to kick it into gear. It sounds as if your router is not opening ports correctly.