Why isn't my alarm going off on a specific day?

Hi,
I have a multiple days alarm options, same times the alarm not work on Thursday.

options set:
6:40 am Monday and Wednesday
7:20 am Thursday
7:35 am Tuesday and Friday
9:45 am Saturday (Turn off)

Lumia 625
SO: 8.10.14219.341

Thanks,

Have you checked to see if the volume is turned on for this specific day? Like in the alarm itself?

The volume is on. No volume problems.
Icon is OK = Alarm work
Attachment 96980
Icon not show time = Alarm not work (But settings is on)
Attachment 96981
My settings:
Attachment 96983

To resolve I need open the settings, turn off and turn on again. After that icon show time and alarm work again.
thanks,