Sound issues on iphone 15 pro max

I recently purchased a iphone 15 pro max. Frequently when I play anything with sound such as a video or music through a streaming service, the volume level will start normal then after several seconds decrease significantly on its own to the point it doesn't even sound that it is coming through the phone speaker. At that point I cannot increase the volume level when I press the volume button. I have to stop the audio and video I am playing or restart my phone to temporarily solve the issue.