hmmm… ugh. I gotta admit I don’t see anything obviously wrong. what i’d if it were me is to try a couple other “simpler” commands to see if I can get any send event commands working. like try doing the exact thing for mute or volume (if your android TV does it’s own muting)
the other thing is maybe look at
Nerwyn knows this stuff super well. Maybe he knows your android box
not necessarily recommending you abandon what you’ve done. But maybe try that and see if that does channel up/down. If it does, he’s got it cracked. And either the code or his head has the answers