Union member field change to a LOV on 25A

Summary: Currently, my UI receive the 25A. On the Hire page, the union member field change to a LOV (like responsive). I would like to change the fild to the Check button that exist in 24D.

If its nor possible, I wold like to know WHY the field change.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

25A

Code Snippet (add any code snippets that support your topic, if applicable):