I have three TV's - old Sony, 4k Samsung (kind of old too) and non-smart small Samsung TV.
I have two RPi3 with libreelect and TV remote controls work like a charm. I Wanted an upgrade and now I have three RPI4 with fresh libreelec and TV remote is not working at all. I have tried everything that is suggested on the forums, bug reports manuals and mail list to no avail. Invludin "turn of the TV for hour" - which obviously sound stupid but having multiple devices and TV you can afford to keep a pair out of power 
I have read that the same issue is present also on some ubuntu installs and also somewhere that CEC is broken in linuks kernel and is known issue but I have never found the report for this.
Anyway before i start buying different cables is there anyone who ever managed to get HDMI-CEC working with RPI4 and LibreELEC-RPi4.arm-9.2.0.img.gz ?