I recently upgraded the Operating System of a Moto X to Android Kitkat 4.4.4 when the update was released.
After the upgrade, the built-in alarm clock would not go off each morning.
Googled around and found that it was not the only one. Here is the link to the Motorola support page https://forums.motorola.com/comment/767870.
To overcome the problem, I did the following steps:
- Disabled the default Clock app on the Moto X;
- Looked for some alarm apps on the Google Play Store;
- Finally installed this is alarm app https://play.google.com/store/apps/details?id=com.macropinch.axe from Macropinch
Since then the alarm does go off correctly. I think the reason for it failing may have to do with the alarm sounds, because Oxygen and Celium sounds are the same, unless they were made to sound identical.