FiOS TV One HDMI-CEC Auto Switching Issue

[MOne3]

I just received the new FiOS TV One set top boxes (Arris VMS4100) and enabled HDMI-CEC.  I have all my equipment routed through my Pioneer receiver (PS4, Roku, Switch) to a Samsung TV and they all work perfectly to automatically switch the receiver input when powered on.  However, this new STB does not automatically switch.  I know that HDMI-CEC is working, because the receiver's standby passthrough is working (which requires HDMI-CEC).  However, when looking at the list of HDMI-CEC devices listed on the television, the Arris STB is not listed, or it is sometimes listed but when I attempt to connect it times out.  If I bypass the receiver and connect the STB directly to the tv, I can see the STB listed as an HDMI-CEC device.