Apple tv box 4K remote control

I have been trying unsuccessfully to control the volume of my Bose soundbar with the Apple TV Box remote control. I tried with "apple support" and several sources of online queries without success. I found many people with the same problem: "after the "learn" procedure" nothing happened". Finally I found a solution, at least for the "Bose Soundbar", doing the whole "learn" process, as indicated in the "settings", but with the soundbar on "off". It works now without problem.