Galaxy S7 audio cuts out, how can I stop this?

Hi

I've had my Galaxy S7 for almost two months out and the last few weeks the sound keeps cutting out. This doesn't happen whenever I get called or get a text, but only when I try to watch a video either on YouTube or Facebook or one that's on my phone. The sound will play for only 2 seconds when it stops. It also happens when I try to set a ringtone.
Does anyone know what's going on? Is this common?

Please help.

I didn't find the right solution from the Internet.

References:-
https://bit.ly/2sSjBVR
App video production company

Thanks