Hi. I believe that the Denon 2309 can either process the audio over HDMI (i.e. play it through the speakers connected to the receiver) or pass it out through the HDMI output (so that you can listen from your TV), but it can't do both at the same time. Your owner's manual should give instructions on how to switch between processing the audio and passing it through.
You may also need to set the audio input and video input independently for whatever source input you are using. As an example, if you are trying to watch and listen to a DVD player using the "DVD" selection on the receiver, you may need to set up the HDMI input to which you connected the DVD player as the audio input for "DVD", and then set up that same HDMI input as the video input for "DVD".
In addition, make sure that you select the correct HDMI video input on your TV when you choose which video input to display.
Just let us know if that doesn't solve your problem, and I'll look through your manual and help you out.