Googling a bit suggests it was introduced in hdmi 1.2 and updated in 1.3 - thinking about this it’s possible cable or TV version has impact on your functionalit

Googling a bit suggests it was introduced in hdmi 1.2 and updated in 1.3 - thinking about this it’s possible cable or TV version has impact on your functionality - E.g Kodi sending a newer CEC command because your cable says it’s fine but the tv cannot process (this is purely a guess btw, but I’ve seen dumber things). You might be able to find some cli tools that help troubleshoot, but yeah, not an expert here.