I cannot even begin to express my frustrations right now.
This is the old thread I started, with explanation of what was going on with my C5400. Basically; the 2.4GHz network is dying after only 1 year of owning the router.
I requested an RMA after sticking it out with tech-support and going through multiple redundant tests, which produced no results. Finally my RMA was approved, and my new unit was sent to me. I unboxed and plugged in my replacement unit today to be greeted with the message "The 5GHz network cannot be used due to restraictions in your region/country."
I live in the US and am on FiOS, 5GHz wifi is not restricted. I must have been sent a defective router, or one manufactured for a different region of the world. I don't even understand how this could happen. I'd very much like to actually get a fully-functional replacement for my replacement (ha) that hopefully works for more than 1 year. On top of all that, the C5400 is NOT a cheap router...I cannot believe I paid that much money for such a product, and service like this.