Troubleshooting : App setup
Short answer
Ensure that your source device is Bluetooth-paired with the speaker before beginning the app troubleshooting
Download the Marshall Bluetooth app.
Press and hold the Bluetooth® button until the LED changes to a slow red pulse to enter pairing mode. Select Stanmore III from the Bluetooth list of audio devices.
Open the Marshall Bluetooth app and tap the + sign to add the device to the app. During the connection process, the Stanmore III [LE] pairing request appears and must be accepted.
Connect the Stanmore III to the Marshall Bluetooth app to verify that the firmware is up to date. You can verify that the firmware is up to date in the 'About' section of the app.
If the issue persists, perform a factory reset. Also, remove/clear the speaker's name from the Bluetooth list and clear your phone's Bluetooth cache.
How to clear the Bluetooth cache
Clear the Bluetooth cache on your Android phone
Go to Settings on your Android device.
Select Apps.
Click ⋮ to show system apps.
In the list of apps, select Bluetooth, and then select Storage.
Tap Clear cache and exit the settings.
Clear the Bluetooth cache on iPhone
On your iPhone, go to Settings.
Tap Bluetooth.
Find the Bluetooth device causing the problem and tap the 'i' icon next to it.
Select Forget this device.
Turn Bluetooth off and on and restart your phone.