Apologies if this is elsewhere but perhaps all HDMI-CEC problems could be linked from the one post.
There appear to be many different effects for different users with differing equipment.
When I bought my FVP4000 I also bought a decent 1 input 2 output powered HDMI splitter so that we could watch in either the main room or Kitchen/Dining room. Initially there were issues due to the fact that the FVP had been connected to my main TV directly and now it was going through the AV amp, the TV kept remembering the original AV input and switching to that. After powering off everything the amp and TV in the main room and the PS4 and TV in the kitchen and then starting them all one at a time all seemed well, with excellent signals to both rooms.
Somehow though turning the PS4 on or off in the kitchen resulted in the front room TV switching AV source, also HDMI-CEC function which had been fine on the PS4 now acted erratically. I blamed the splitter for passing all signals between all connected devices and sent it back (I still think it was partially to blame)
I now simply use a Female Female connector on the end of the HMDI from the FVP and change connection manually to the TV's HDMI I want to use.
If the FVP4000 is connected to my main TV via the AV amp, HDMI-CEC for the TV goes erratic and the ARC signal is blocked, but the FVP4000 HDMI functions all work and I can use the TV controller for the FVP.
If the FVP is connected to the Kitchen TV with the PS4 then the PS4 HDMI-CEC fuctions are blocked.
So the FVP4000 is leaving the signal on; I have read there is a connector which leaves the associated pin in the HDMI lead disconnected to stop that. But then all HDMI functionality would also cease.
If I go that route then I believe HUMAX should supply the connector due to poor design. I have signed up for the Firmware test and hope that the HDMI-CEC signal may be controlled via the software. Any thoughts if it can be resolved in the software.
Sorry for the long post
Both TV's are Samsung if it helps.