Why does my mobile phone alarm at twelve o'clock every night?

For the mobile phone with the model "OPPO-Reno5-Pro", it may be that the alarm of the mobile phone has not been turned off, so just turn it off.

1. Click the time on the mobile phone desktop, as shown:

2. Enter the alarm clock setting interface, as shown:

3. Slide to the left to turn off the zero alarm clock, as shown in the figure:

In this way, as long as you turn off the alarm clock setting, there will be no more alarm clock ringing.