Probably the device connection between the mobile and the app has lost and you may try these steps below:
1. Remove the device under the Bluetooth settings.
2. Uninstalled the apps.
3. (Only for Android users) Turn off Automatic Restore of backed up settings and data.
4. Re-install the apps and connect the device again under the Bluetooth settings & apps.
If the problem still persists, you may contact our support for more assistance.