That seems odd…but power surges, especially when power comes back on are frequently odd. I’d try a reboot (unplug, wait two minutes, plug back in) your Sonos devices, which will force them to reload the OS and reconnect to your router. In fact, it might not hurt things to reboot your router while they’re unplugged, but I don’t think that would affect this particular issue, it’s just a good idea, especially if there has been a ‘surge event. It may have impacted the router, it may not. 

Then do a test. Set up an alarm for five minutes later. Let it go off, and see if it bothers you works properly, and exists after you’ve quieted it. If not, I would recommend that you submit a system diagnostic within 10 minutes, and call Sonos Support to discuss it. But don’t post the resulting diagnostic number here, they get sensitive about GDPR.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

Did you ever find her fixed to this because I’m having the same issue?  
 

All my alarms disappeared. I created new ones they disappeared. I rebooted everything. I rebooted my phone even. I deleted the app and reinstalled the app. Nothing seems to be working. 
 

This morning for a split second all of my alarms came back. And then disappeared again within a couple minutes.

Hi, I’ve already for some weeks the same issue. Alarms work from the PC app or from my Lyd app on my apple watch, but not from my phone app anymore (IOS18). Not 100% sure but I’ve the feeling that it started when my phone was updated to IOS18. Two problems are now present:

• The above described alarm issue
• The recently played list disappears immediately after starting the app on my iPhone

As the PC-app and Lyd are still working, I don’t suspect the network or sonos components, but something seems broken in the (IOS?) app?

What did Support say, when you provided data to them and called in?

Have the same issue. Recently played page is also ‘unable to load content”. To make matters worse, the pre-existing alarms are still active and I am unable to turn them off. 

New situation on my side: since this week-end all is working again normally. Only change: my iPhone was updated to IOS18.2.1

So, I’m not sure if it was due to the update, or a full restart of the phone but anyway all is working again now.

I couldn’t add an alarm after deleting one that I was using . I have deleted and downloaded the Sonos app again . Deleted all alarms as other posts have said and start again . Still will not save an alarm.

I would have thought it would have been fixed months ago . Wish I had never touched my alarms now . Seems a software issue that ​@SONOS is ignoring or seem to think is fixed . Not sure what the dev test team are doing or quality control department are doing but the app is buggy at  best and removes speakers etc at will, plus makes it the hardest thing on the planet to reinstall a speaker . 

Anyway . I bought my last ever Sonos speaker . Will move to another manufacturer. I do not want to be a beta tester for a very expensive and what used be a great speaker system . 

I know , close the door on my way out ;o)