Alarms appearing that I didn’t set?

Hi everyone,

for the second night in a row, an alarm that I haven’t set has appeared and gone off in the middle of the night.

The first night it was at 1am. I know I didn’t set it so changed my passcode in case I had fallen victim to a practical joker at work. But last night, it happened again but at 12:22?

These aren’t random alarm noises just going off - they are actually set alarms that display along with my usual ones I have set for morning time.

Any advice?