Does "Do not disturb" mode prevent checklist alarms from sounding?

Yes. If your tablet has Do not disturb mode enabled, checklist alarms will not be sounded.

Check the Settings on your device and make sure that Do not disturb is disabled:

• Swipe down to display quick settings and tap on Do not disturb if it is enabled.
• Open Settings, then Notifications, and disable Do not disturb if it is enabled.