Why Airflow is raising an SLA?

Question

I don’t understand why SLA’s sometimes are triggered.

An example is a dag with an SLA of 'sla': timedelta(hours=1)

I received an email with this:

Here’s a list of tasks that missed their SLAs:
APP_task_group.copy_events on 2022-05-08T03:00:00+00:00

But checking the graph view in the UI I see it started at 04:28 and finished at 04:46, which is range of one hour.

I understand that the SLA is starting in the real UTC time when the dag starts, so the dag with id 2022-05-08T03:00:00+00:00 has between 04:00 and 04:59 UTC to run without raising an SLA.

Am I wrong? What does explain why this SLA is raising?