Alarms no longer work after marshmallow update

[LeeAnne42]

I updated my phone to 6.0.1 from 5.0.1. After which the alarms no longer work the same.
When the phone is in lock screen and an alarm goes off: the screen comes up blank with only the wallpaper and no option to tap to snooze, or swipe to turn off alarm. I have to hold the power button, and restart the phone to turn the alarm off.
The same error occurs on safe mode.

I performed a full wipe and restore and the same error is still there in both safe mode and normal mode.
When the screen is not locked the alarms work correctly.
 
I have been told by Sony support line that the update caused a hardware fault and I have to send it to be repaired in Sydney.
Any other suggestions? Because I dont like that one Kind of desperate for a solution that is not that.

[MarlonUk1]

if it is a hardware issue then there is nothing else we can do but to send it in at your Local support service center.

another way be more messy and will invalidate your warranty, flash another firmware using flashtool or Xperifirm

[LeeAnne42]

I do not understand how a software update can cause a hardware issue. And is there a way to confirm it is a hardware issue without being without a phone for a week (minimum I'm guessing)

[MarlonUk1]

try to do a factory reset and a software one more time. do not install any other apps for the meantime. try to replicate the problem,

or try to use another launcher, maybe the problem is just localized the built it app. try using google now launcher and 3rd party alarm clock. try

[LeeAnne42]

I'll try a third party alarm and see how that goes. thank you

[PDGL]

I am having exactly the same problem as you, and I have tried a fresh install of the system software and still the same problem. This is obviously a bug with the system software so why aren't Sony fixing this issue? How could this be a Hardware issue?

I will also try a 3rd party alarm instead of using Xperia.

[Rickard]

I'm very sorry to hear that 

After you performed the software repair, did you restore any backup to the phone?

I've been testing this here but this doesn't happen in my Z2. When it happens, are you able to unlock the phone and access the phones menues?

[LeeAnne42]

After I performed the software repair I restored to a back up taken that day.
I didnt add any apps to it. I opened in safe mode and the phone did the same thing.
There are also issues with the basic apps closing when I am in them ( writing messages, making calls etc). The screen goes dark grey and I have to press the power button to get it to come back.
But the alarms is my issue- I rely heavily on those.

[Rickard]

It may perhaps be something in the backup causing this.

Could you first try to clear data for the clock? Please note that this will delete all alarms so you have to set them again.

To do this, go to Settings -> Apps -> [menu] -> Show system -> Clock -> Storage -> Clear data -> OK and then restart the phone.

[Rickard]

@LeeAnne42

Did it help to clear data for the clock or does the alarm still not work?