Requirements:
Set up custom workflow from: https://doc.ibexa.co/en/latest/content_management/workflow/workflow/#workflow-configuration
2 users: 1 default admin and 1 default editor

Steps to reproduce:
1.  Create a draft with admin user
2. Send it "To legal" according to workflow, assign editor
3. As the editor click back to draft

Actual result:
The selection of the user "reverse: to_legal" looks incorrectly

Expected result:
To be discussed. From the workflow point of view there is no need to select any user. Using action reverse should point into the original owner of the previous step- in this case editor. 

Notes: 
The user for proper working of this workflow is not required at all. You can leave the textbox empty.
If you setup the workflow, that you need to select user, the dropdown works correctly.
From my point of view its minor UI bug on the component, that shouldn't be visible in this situation at all.