Hi Leighton. Maybe you are accidentally holding the volume down button maybe like when it's in your pocket. Also, while in home screen, press the volume up button, check if the volume automatically goes down.

Why should I buy the Motorola Moto G6 when I had the Motorola Moto G3 and it was terrible?

Hi Geraldine. Experience may differ depending on your usage. Looking alone at the reviews of Motorola Moto G6, it looks good and worth its price. If you're huge on playing games, you might want to check the pricier version which is the Motorola Moto G6 Plus or if you just like using the phone for social media and need that juice when you're night out, check the cheaper version which is the Motorola Moto G6 Play.