iOS Alarm Bug or Intended?

Every morning my alarm goes off, I reach out while still sleepy to grab my iPhone. And sometimes the alarm stops the moment I touch the phone. Super annoying. And the weird part is I can’t reproduce it during the day.

This morning, LORD let me see something really strange. While the alarm was ringing, I swiped up from the bottom-right corner of the lock screen (kind of like pushing the screen upward from that corner), and the alarm stopped instantly. How strange.

Is this some iOS thing Apple intended, or is it a bug / accidental gesture that cancels the alarm?

Please refer to this image: https://imgur.com/a/mXGEZJp