Media Library Renamer doesn’t work

Hi there.
We like how this operates when you Edit Image, but it’s a length process.
The Media Library in List view, shows the box to rename, but it doesn’t work. It’s the ideal place to do it, so you can ‘whiz’ through them.

Can you help us identify the cause of the problem please, and make this renaming process much easier for us, when we have 100s of product filenames to rename.