For the past 2 month my LG g4 phone cell signal became very bad. Never had problem in my house, but now 1 out of 5 calls get dropped. It looks like the only time i can talk on the phone is outside.
Welcome to Android Central! Who's your carrier? Have you discussed this with them? Do they offer a signal booster or microcell for the home? Do other phones on the same network have the same reception problem inside your house?
The router shouldn't matter, since that's for wi-fi. Unless Verizon has special signal boosters that act as routers as well (like T-Mobile).
If all Verizon phones get poor signal in your house, then there might be a problem with your nearby towers. Definitely give Verizon a call, and ask to speak to one of their tech support people (not the customer service reps).