Xiaomi
Change Alarm Tone auf Xiaomi
On Xiaomi devices running MIUI, alarm tones are managed through the sound settings rather than inside the Clock app itself. This separation is why many users cannot find the option they expect directly in the alarm screen.
To change the alarm tone, open Tap on Settings ➔ Tap on Sound & vibration ➔ Tap on Alarm ➔ Tap on All ringtones ➔ Choose a ringtone/notification sound. From this list you can pick any installed ringtone or notification sound as your alarm tone.
Why some tones change automatically
Certain entries, such as the Nature alarm category, are not a single fixed sound. Instead, they rotate through a set of nature recordings and fetch a new one each day.
This rotation only works while the phone has an active internet connection at the time the alarm is set or triggered. Without connectivity, MIUI falls back to the last downloaded or a default stored tone, which can look like the setting is broken when it is actually a missing network issue.
If you want a tone that never changes and does not depend on a connection, choose a standard ringtone or a locally stored audio file from the same menu instead of a rotating category.
Keep in mind that changing the tone here applies to the alarm you are currently editing. Other saved alarms keep their own individually assigned tone unless you update each one separately.