The latest Android OS utilize new battery settings which "optimize" your power consumption and can interfere with your Informant alarms on your Android device.

You'll need to adjust your device settings (not informant) for battery optimization for the informant app. As an example, on a Samsung device you can use the steps below to add Informant to your Unmonitored apps list:

1. Open Android Settings > Tap "Device maintenance" > Tap "Battery"
2. Tap "Unmonitored Apps" > Tap "Add apps"
3. Select "Informant" to add it

If you have a different device or your settings don't appear the same, you will need to contact your device's support or do a quick search online for how to do this. These settings are all done outside of informant.

Then go to informant settings>alarms>choose click here to change alarm sound settings, then tap Informant under "Categories", select sound, and choose your desired sound.