Issue types dropdown in the "Child Issues" panel contains custom issue types

Issue Summary

This is reproducible on Data Center: no

Steps to Reproduce

1. Open an issue with issue type at hierarchy level 1, for example, an epic
2. Click the "Add a child issue" button

Expected Results

The issue type dropdown only contains issue types at the hierarchy level below

Actual Results

The issue type dropdown contains issue types at the hierarchy level below, and additionally, issue types at custom hierarchy levels (1+).

Workaround

In the dropdown, select the issue type at the hierarchy level below.