Event reminder doesn't triggered when select "Sounds" option only in system settings.

Information:
phablet@ubuntu-phablet:~$ system-image-cli -i
current build number: 63
device name: krillin
channel: ubuntu-touch/rc/bq-aquaris.en
last update: 2016-09-05 14:09:38
version version: 63
version ubuntu: 20160903
version tag: OTA-13-rc
version device: 20160606-ab415b2
version custom: 20160831-991-38-18

Step:
1. Open system settings and goes to notification section
2. Tap on Calendar app
3. Select "Sounds" option only
4. Go to Calendar app and add a new event
5. Set the trigger is "on event" and fill in others form.
6. Wait to the event time

Actual result:
No sound trigger at the event time.
(Also, in system settings > notification, Select "Sound" and "Viberation ", "Notification Bubbles" ,"Sound" and "Viberation ", No trigger happened at all.)

Expect result:
Only the sound triggershould happened as the settings set.