111
Borked alarm rule
(sh.itjust.works)
Be sure to follow the rule before you head out.
Rule: You must post before you leave.
Did you have to manually unlock your phone instead of fingerprint or whatever?
Nope.
I even disabled battery saving for clock app, locked it in recents, disabled cache clearing when device is locked.
This only happened to me twice after these precautions, but, MIUI. It's quite buggy, so I don't know if it's power saving or just buginess.