What extender model, and what router model are you using? Yellow solid means the extender can't link up to the main router.
It is recommended to connect the extenders back to the main router by using Ethernet or Coax. This provides the best performance, and also solves for problems encountered where the signal from the main router is too weak for the extender to use wireless backhaul.
Also, not all Verizon Fios routers can wirelessly connect an extender. Hence my ask about what Verizon router you have. G1100 and CR1000A will require Ethernet or Coax backhaul IIRC. If the router is an ActionTec, it's in need of an upgrade.
Did you ever get this resolved and if so, how?
did you connect extender per coax to router?
Any response on this???