You cannot use your Verizon IR remote to change TV channels on your Verizon FiOS Set Top Box if you point the front of the Pixel 2 towards the set top box.
My Verizon IR remote stopped working, I did everything to get it to work, I changed the battery's, I power cycled the the set top box, I got anther remote, etc. It turns out when I placed the Pixel 2 on the stand next to my bed to charge over night, I faced it towards the Verizon FiOS Set Top Box, when I placed the phone face-down, or in anther direction away from the Set Top Box, I was then able to use the remote to control the Set Top Box.
I even tested this with anther Set Top Box in anther room, Facing the Pixel 2 in the direction of any Set Top Box, prevents the IR remote from controlling the Set Top Box.
I do not know what the Pixel 2 is doing to prevent the STB remote from working, I disabled WiFi and Bluetooth, and the phone still keeps the remote from working.
So, if your Pixel 2 is in the same room as your STB, be sure not to face it towards your STB, it will prevent you from using your IR remote to power the STB off or on, or change channels, etc.