- Reminder doesn’t work?
Please check if the reminder switch is on, and the AM/PM setting is correct. Also, the timing is inexact and could be late up to 60 seconds, and this is to decrease power usage.
Maybe some power saving or cleaner apps on your device interfere with the reminder or you have low available memory, try cleaning up some unused stuff or try restarting your device.
This issue may also be caused by Doze feature, which represents battery optimization in Android 6 and higher. You should disable battery optimization for this app so it will not interfere with the reminder, by following these steps:
1. Open the Settings menu on your device and tap Battery.
2. Tap the more button on the action bar at the top right (…), and choose Battery optimization.
3. On the Battery optimization screen, switch to the All apps list from the drop-down to see all of the apps on your device. Tap Drink Water from the menu and choose Don’t optimize.