The calculated value of the alarm is always below the alarm threshold, and the alarm is triggered only when the alarm rule is created and the service is restarted

[cxposition]

Set memory alarms. The alarm rules are as follows:

The corresponding alarm chart is as follows:

In this case, alarms are recorded only when the alarm is created and when the query-service service is restarted. It is unknown whether the fault is caused by the alarm rule configuration or back-end code processing. The alarm history is as follows:

Expected behavior
When the threshold is always greater than the alarm value, a message is periodically sent to the channel.

question:
Is this a query-service problem or a panel query statement configuration problem, and how to solve it?