VIZIO V21-H8 36" 2.1 Home Theater System

This item arrived in 3 days, which is a week or so before it was scheduled to arrive. That's nice, and the sound is nice, but everything else has been disappointing. Firstly, the package appeared to have been opened and then resealed. All the contents appeared normal inside, but there was no AC power cable. So I made do with the cable from my old TV. I set up everything else according to the instructions, connecting the sound bar to my Hi Sense TV with the HDMI ARC cable. The main problem is that the sound bar doesn't take priority as the audio output when I turn on the TV. The sound bar only comes on once I adjust the volume, or mute and unmute the volume (using the TV remote). I've tried the different audio settings on the TV and just can't get the sound bar to come on instantly as the audio output. Once it comes on, the audio sounds great.