I currently use my Razer Blade Stealth to watch movies on using a HDMI cable which connects to my receiver which goes to my projector. For some reason when I am watching, audio will cut in and out at random times for up to 5 seconds at times. I tried multiple HDMI cables but same result.
Many receivers develop audio problems due to HDMI switching going bad.
Try using a different HDMI source to check out the receiver HDMI circuitry.
You can also check the receiver with an analog audio input like the FM tuner if you have an antenna connected. You could also use the analog audio output of the laptop instead of HDMI to try check the receiver.