Huawei
Change Alarm Tone auf Huawei
On Huawei phones running EMUI, every alarm gets a default tone unless you pick one manually during setup. This applies to brand-new alarms and to alarms you created a while ago, since the sound option stays editable at any time.
Where the alarm tone setting lives
The sound picker is not on the main clock screen. It only appears once you open the details of a specific alarm, which is why many users never notice it exists.
To change it, tap on the clock app, then tap on an alarm you want to edit. Inside the alarm, tap on Sound and choose an alarm tone from the list. Tap on back once you have made your choice, then confirm with save so the new tone actually applies.
If the alarm still plays the old sound afterward, check whether the save step was skipped, since leaving the screen without confirming discards the change.
This method works the same way for alarms you are creating for the first time and for alarms that already exist on your device.