On my PoCo phone, google clock was being killed during the night to preserve battery, even if I set it to "unrestricted". I have to use the MiClock for my alarm.

Do you have a smart watch? I have a client who had no notifications coming in sometimes but not others and it turned out it was his watch taking over notifications. Disabling it was done from the watch and took effect immediately.

I vaguely remember some issue like this.

If I recall correctly I went to the list of all applications and checked the notifications and permissions from there because it shows more options.

But I also remember something related to hiding content out of the lock screen, possibly I tried to hide content out of the lock screen and had to revert that.

I know I'm not being very specific but maybe it can at least give you ideas.

Looks like you're connected to something via Bluetooth. Is it a pair of headphones? Could your alarms be going off and playing through them? That's happened to me a couple times.

I'm willing to bet that when you transferred your old phone's backup, something likely doubled-up on this recovery after the fact, and there's probably some busted metadata somewhere in your app settings. Try this:

I always recommend uninstalling the updates first when a system app is misbehaving, because they tend to back up slightly differently than regular apps do, and seem more prone to errors after restoring, in my experience. Settings > Apps > Find "Clock" > Three dots menu in the top-right > Uninstall Updates. Then go to the Storage & Cache option on that page, Clear Storage. Then go to the Play Store, find the Clock app and install whatever updates are available. Set the alarms back up and catch some Zs, and see if you wake up on time.

Alternatively, you could look for a better alarm clock app. The Google Clock app is fine enough, but I find Sleep As Android to be much better for wake-up alarms. It's got sleep tracking, and will try to wake you up slightly early if it detects that you're in an optimal sleep phase to wake up in, or it'll just go off at the set time if you don't cycle into an appropriate sleep phase in time. There's also a ton of options for different types of alarms (puzzle/math alarms, QR code alarms, etc). The free version is already pretty good, but the full version is 100% worth the purchase, IMO.

Try turning up your media volume. Might be that the system is confusing this app's audio for media instead of a true alarm.

Have you tried another app yet ?

I'd try a different alarm app before delving this deep. Yeah its an issue, but its really easy to go to F Droid or Izzy and get a replacement app.

That sounds really frustrating. What kind of phone is it?

I use Fossify Clock and I'm having the same problem.

Gentlemen, it is with great pleasure that I announce my alarm went off this morning and I arrived at work on time.

Unfortunately, with all the fiddling around, I'm not sure quite what I did to fix it. I think that maybe just uninstalling and reinstalling the clock app from Google play fixed the problem. Either that, or fully disabling my scheduled Do Not Disturb function.

EDIT: I spoke too soon. My alarms didn't go off this morning. BUT I think I know why now.

It turns out that there were two apps called Clock. One that was cloned from my old phone, one that came with the new phone:

All my alarms were set up in my old clock. But when I'm giving permissions and exemptions in the battery manager, I reckon thats affecting the new app, which has no alarms. So the old clock app is still getting randomly killed in the night.

I've uninstalled the old clock app and set up alarms in the new clock app.

I reckon that will fix the problem tomorrow, but I'll have to wait and see.

One way to check is to make a new alarm for ten minutes earlier or later than the old alarm, and see if that one sounds. I have DND turn off half an hour before my alarm goes off, but it also is supposed to ignore the alarm altogether (not interfere with alarm settings/sounds).

You may also want to see if the alarm is sounding on the old phone (if you haven't already wiped it, sold it etc).

Turn notifications,ring and call up.

Make the clock uses a different volume setting?

Did this ever work? Have you tried factory resetting the phone and setting an alarm first thing? Maybe there's some setting you managed to change and can't find again. I know Android settings menus are a maze.