I know this might sound straight forward but that’s not the case in Unreal Engine. It’s possible after moving an asset a folder will show up empty inside the editor, but on disk it will still contain files. This is happening due to Redirectors.
<aside> 💡
Running this operation will trigger a Fixup redirectors operation beforehand to ensure the folders are empty.
</aside>

To quickly fix all empty folders in your project, navigate the Toolbar menu and start the Cleanup empty folders operation.
Select the folders you want to clean up and use the folder context menu to Cleanup empty folders.