Problem with connecting my laptop to my TV through HDMI

I don't think many people do it but I enjoy connecting my laptop to my television through HDMI. My laptop enables me to watch and listen to content through the TV.

For some reasons, the sound plays through my laptop and I can get my TV to display everything I want through my laptop. But sometimes sounds don't play through my laptop and I wonder what to do because if I go to the control panel on my laptop I can see the option of sounds from my TV but it doesn't work if I try to enable sounds from it.

The main problem is I see the arrow pointing next to my TV icon and saying 'Not plugged in'. It wouldn't let me set it as default or configure. 

What could be wrong?