Hi,
I'm Diego Rios, an Independent Advisor willing to help other Microsoft customers.
You can try to turn on the notification with the procedures below:
Try to run the Apps troubleshooter to fix issues that may prevent app from working properly in the link below:
https://support.microsoft.com/en-us/help/402749...
Press the Cortana button on the taskbar to open that app.
Enter ‘Control Panel’ in Cortana’s search box.
Select to open the Control Panel,.
Click Power Options to open the tab.
Click Change plan settings > Change advanced power settings..
Double-click Battery to expand its settings.
Click the + beside Low battery notification to expand the options.
If the On battery and Plugged in options are off, select On from their drop-down menus.
Press the Apply button to confirm the changes.
Click OK to close the window.
Then, Configure the Low Battery Level:
Open the Power Options window again (which includes the battery notification settings).
Click Battery > Low battery level
Select On battery and enter ’20’ in its text box.
Enter ’20’ in the Plugged in text box.
Press the Apply and OK buttons.
Please let me know if this helped and works.
Best Regards,
Diego R.