Deleting Anchor Sprint from PI removes data from UI but does not delete from backend

Issue Summary

Deleting Anchor Sprint from PI removes data from UI but does not delete from backend. You still can retrieve data using API.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Create a Program Increment
2. Create Feature under Program Increment
3. Create 2 anchor Sprints in the Program Increment
4. In the Feature created set Start Target Sprint and End Target Sprint
5. Go to Program Increment and Remove one of the Anchor Sprints
6. Check the Feature in the UI and Target Sprint will not appear
7. Check the Feature via API using GET and the Target Sprint value will still appear

Expected Results

Anchor Sprint to be removed from the backend as well

Actual Results

Anchor Sprint is not deleted from backend and can be retrieved by API using GET method.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available