Flapping outside service period is incorrectly included in SLA calculation in reports

CMK version: Pro 2.4.0p27
OS version: Ubuntu 24 LTS

Error message:

We’re using monthly reports for reporting the avialability to our customers.
Following configurations were made:
Time Period “9to5”: Monday–Friday 09:00–17:00

  1. Service Period for services: correctly applied to the affected service via rule (confirmed via “Parameters for this service”)
  2. SLA definition: monthly period, Computation Type “Service state percentage”, OK minimum 99%
  3. SLA requirement: “Active in timeperiod” = 9to5
  4. SLA option “Service Time”: “Base report only on service times” enabled
  5. SLA option “Consider periods of flapping states”: disabled

Bug description:

A service was flapping exclusively outside the configured service period – specifically from 17:45 until 08:45 the following morning. Despite a correctly configured Service Period and the option “Consider periods of flapping states” being disabled, the flapping is still included in the SLA calculation.

Expected behavior: Events outside the Service Period are not included in the SLA calculation.

Actual behavior: Flapping outside the service period appears with 1.27% in the SLA calculation, causing the OK value to drop to 98.52% and the 99% SLA to be reported as broken.

Has anyone the same problem and a solution for that behavior?

Thanks in advance!
Regards,
Marcus