If the volume adjustment of the speakerphone is abnormal, for example, the audio output gets really quiet or goes to extra loud on its own, please try these steps to resolve the issue:

• Try the speakerphone with a different device
• Test if the issue persists in both Bluetooth mode (connecting the speakerphone with your device via Bluetooth) and USB mode (connecting the speakerphone with your device directly via the included cable) 
• Update the firmware of the speakerphone to the latest version
• Reset the speakerphone