How can I find the name of a workflow before change?

You can find the previous name of the workflow (before the name change) by checking the Audit Logs. Simply search for the new workflow name on the page. If you don’t find it on the first page, scroll down to load the next set of records and then perform the search again. This should help you identify if the change was recent. However, it might be difficult to track if the change was made a while ago.