I'm not sure if it is a memory thing, but I just forced my Zero to use the legacy video driver by commenting out the dtoverlay=vc4-kms-v3d line in config.txt and now there is no /dev/cec0.It may well be that the lack of memory is forcing use of the legacy driver and maybe cec-ctl doesn't work with that?
So it is definitely related to the video driver in use.
From raspinfo...
cecctl works:
Code:
Display Information-------------------Running (F)KMS, consoleCode:
Display Information-------------------Running Legacy framebufferStatistics: Posted by rpdom — Sun Aug 11, 2024 2:00 pm