Contact Verizon directly. As this is a Peer to Peer support group. If the router connects long enough to get the guide data then disconnects, the TV may not see the issue, but it would be noticable on your internet service. They will try a router replacement first after performing diagnostics, and if they replace it, you may get a newer router.
They will suggest you try their In Home agent for diagnostics.
https://care.verizon.net/iha/IHAPC.aspx
If after replacing the router you still have issues, as a last resort they will probably replace your ONT. That is the large gray box mounted on or in your home. Some homes are different and have smaller equipment, but mostly that was in some appartments (MDUs). If they run diagnostics on the ONT and see issues, it may require a tech visit, and not a router change.
Contact Verizon.
http://www.verizon.com/support/residential/contact-us/index.htm