I can't get HDMI-CEC to work on my Raspberry Pi 400 using the Libreelec 10.0 BETA1. I tried tweaking the input adapter settings, rebooting, checking the TV's settings... Everything looks good. But the TV does not detect the device, it detects my Odroid C2 with Libreelec 9.x just fine.
My TV is a HiSense H7709 Series (2019) 43" 4K Smart TV