[live streams] with deletions does not delete relationships

[axelfahy]

Description

When using live streams, with the "Take deletions into account", the relationships are not removed on the destination.

Setup of the synchronizer:

Environment

1. OS (where OpenCTI server runs): docker
2. OpenCTI version: 6.4.8
3. OpenCTI client: frontend
4. Other environment details: On the screenshots, left is the source and right the destination.

Reproducible Steps

Steps to create the smallest reproducible scenario:

1. Create an observable, with labels, external references, etc. and a report containing this observable.

2. On the source, go to the report and remove the observable from the report. Update the description as well to be sure that both are in sync.

The description has been updated, but the relationships to the observable has not been deleted on the destination.

3. The same thing happens with labels, external references of the observable. In this example, removing the label1 and the external reference from test.com on the source does not remove it on the destination.

Expected Output

With the "take deletions into account" option, I expected the relationships between the report and the observables to be deleted as well. And I expected a deletion for the link between the observables and the labels, external references as well.

Actual Output

Relationships are still present on the destination.

Additional information

Screenshots (optional)