[PROBLEM] CEC with Optoma beamer and Denon AVR 1910

[rikardo1979]

good point the extender may cause the issue. I know this solution with CAT cables to extend the HDMI connections as is the best way to doing the long distance extension without loosing quality.
Would be worth to check what are exact models of the extenders/spliters, if they have CEC support and also check with the company who installed it and ask if they extend HDMI fully or if they skipped some wires and used just basic cos if they not wired pin 13 than that would be the reason