1. You don't say the make/model of your sound bar.
2. Have you set up the Sound Bar as an Audio Device according to the following website?
3. Did you use the code finder in that link?
4. Sometimes you need to try several different codes. Just put in the make in the code finder, without the model and several different codes should come up.
5. Sometimes you may need to scan for codes. I believe that procedure is outlined elsewhere in this forum, or you may wish to contact URC
If you use the link I provided and use the code finder and say "I don't know the model", you will find about 15 different codes for Yamaha. Have you tried all those codes and entered them for the audio device? Sometimes a particular code for an audio device will do one thing like volume, but not power, etc.
Have you programmed in a code (or codes) for the Yamaha specifically for an audio device, per the instructions in the link?
In my bedroom I connected a Sony HT S100F soundbar to the ignite box using Bluetooth, since the soundbar is some distance away from my Sony TV which is connected to the ignite box using HDMI/ARC. The sound comes through the soundbar and TV speakers, however I cannot control the power or volume of the soundbar with the Ignite remote. The ignite remote only controls the Sony TV power and volume