Alarms (and any other background process) not working issue definitely solved.

[TheRotfler]

It's somehow related to live tiles and charging.
Disabling guilty live tile(s), everything comes back to normal.

 

[taymur]

what do you mean?

 

[TheRotfler]

what do you mean?

Alarms and live tiles stopped working is caused by one or more live tiles not working properly.
Who is facing this issue can solve it disabling guilty live tile from its related app.

In my case, for example, every background process (alarms, live tile, main account sync, ecc) stopped working after disconnecting phone from charger. Well, it was caused by a live tile (in my case, a news app live tile).
Disabling it solved the issue (tested several times, disabling and enabling that specific live tile).

 

[crav4speed]

It's somehow related to live tiles and charging.
Disabling guilty live tile(s), everything comes back to normal.

I was having this same exact problem! After updating to 8.1, every morning when I would take my phone off the charger, all my tiles would stop updating until I soft reset the phone... This drove me crazy for literally 2 weeks!! I then uninstalled the app Hardware Tests thus removing it's live tile. Then everything started working normally after that.

 

[TheRotfler]

I was having this same exact problem! After updating to 8.1, every morning when I would take my phone off the charger, all my tiles would stop updating until I soft reset the phone... This drove me crazy for literally 2 weeks!! I then uninstalled the app Hardware Tests thus removing it's live tile. Then everything started working normally after that.

Glad to hear you solved the issue, too.
MS talks so proudly about its security level but any developer can stop an OS core functionality so easy.. very sad.

 

[hprvez]

Those are coincidences. I used to have the same problem, restart after a charge to make them work again. I didn't do anything and the problem automatically went away

 

[TheRotfler]

Those are coincidences. I used to have the same problem, restart after a charge to make them work again. I didn't do anything and the problem automatically went away

Nope. I managed to reproduce the issue several time, enabling guilty live tile.
Every time I disable it, the issue goes away.
Can't be a coincidence at all. You just don't remember what you changed but, trust me, you changed something (or developer make guilty live tile 8.1 compatible)

 

[emigrating]

I had this on my DPed 1520, but it went away after installing the first update.