WAN coax doesn't deliver the guide. It delivers the internet to the whole home.
LAN coax delivers the guide and vod and widgets and whole house DVR functionality.
Is the internet working in the home? if so don't worry about the WAN coax light
Unless you have WAN Ethernet from the router to the ONT, the WAN coax should be connecting to the ONT to receive the Internet and the Guide. If you have Quantum Internet, you may have Ethernet WAN and not coax WAN, and in that case the WAN would function in the same fashion but no coax WAN light, just Ethernet WAN. The Lan coax (MOCA) should be distributing the guide to the STBs/DVRs. The Ethernet Lan goes to your PCs, if you have any that are hardwired.
Do you have the internet working, and the guide is working for the one STB? If so, I would say power down both boxes (unplug the power), reset the router by pressing the recessed button for about 15 to 30 seconds on the back of the router doing a complete reset. Release the button, and wait for the router to show the internet green light. Then plug the boxes in one at a time. Wait for the box to come up fully active, and display the guide before going to the next box.
One last item is if it is a new install, there may be a coax splitter that is not bi directional on the coax drop to the second box. It could be hidden in a wall or almost anywhere. Did both boxes work and one just stopped working? Or did you attempt to install the second box and cannot get the guide? What are the box types? DCT-700 adapter does not receive a guide for example.
Also after performing the reset of the router, or installing a new router, you will need to go to the STB help screen and In Home Agent, the perform the fix or reset of the Caller ID if you have it enabled and wish for it to function. And accessing the a DVR remotely may reqiure you to disable the funtion in the settings, and then re enabling it for it to work.
This is a peer to peer support community, where we all try to help each other. Verizon joins in from time to time, but if you still have unresolved issues, I would contact them directly for more assistance.
If the WAN coax light is not lit on the router, then it's not getting a signal from the ONT.
Do you have internet connectivity from your PCs?
The STBs store up to 10 days of guide data, so you may not notice lack of guide data right away.
A better test of STB connectivity is VOD.
You should check your MOCA stats (both MOCA WAN and MOCA LAN).
You might also try rebooting the ONT.
p.s. How is this an IP conflict (your thread title)?
On the STB that does not work you can go to the Menu and go to Customer Support and run Self Diagnostics and report the findings. Here it should show the network information and signal db to the STBs. If there was a conflict with addresses that is unlikely, it would show here.
Also you can go to Menu, Customer Support, Network Status. Network status should report if the network is being found.
If it is a cable or splitter issue. You may wish to try swaping the splitter port for the box that is giving you trouble, and the reseting the box with a power cycle. Try swaping the box locations to see what happens. But the Self Diagnostics report mention above should give you some information, if the Network Diagnostics do not.