Moving an issue with tasks to a new iteration only moves the issue and not the related tasks

Summary

Moving an issue with tasks in a new iteration does not move the tasks associated with it.

Steps to reproduce

• Create a new group.
• Create several iterations in it.
• Create a new project in this group.
• Create a new issue in the project & associate it with the created iteration.
• In the issue, create several tasks.
• Re-assign the issue to another iteration.
• Check the iteration assigned to the child tasks.

Example Project

https://gitlab.com/atanayno_premium_group/test-iterations (private project)

What is the current bug behavior?

Child tasks should be moved to the new iteration when a parent issue is moved.

What is the expected correct behavior?

Child tasks are not moved to the new iteration when a parent issue is moved.

Relevant logs and/or screenshots

n/a

Output of checks

This bug happens on GitLab.com.