curves went to zero but didn't have a report?

Let's take a look at the CPU and Memory charts for this machine:

At around 01:00pm, the curves went to zero.

Above, the cpu and memory used 0, but I didn't recevie a RED Alert report and email. (if there is some mothed to check this problem).

Hobbit-client configured file

UP 1h 22w

LOAD 5.0 15.0

DISK / 80 90

DISK /boot 80 90

DISK /var 80 90

DISK /data 80 90

MEMSWAP 40 60

MEMACT 80 90

MEMPHYS 101 101

This configuration only reported when the cpu and memory reach 5.0(cpu) and 80(memory), then they will send a alert report and email. But I can't find about cpu and memory used 0, then send an alert report and email. Can you teach me how to do it? Thanks.