This is the end user screen view. When the user selects the Autofill button:
the configured fields will populate the value based on the last record. Fields must be visible in the workitem page to populate using the autofill/“use previous values” button.
The Autofill values are stored in browser local storage. These values are saved when the index button is clicked during Batch Indexing.
If there are no Autofill values available in Local Storage on page load, the current values of the document are saved. Then again, after Indexing with Index button they are saved over.
You can check your current saved values in Developer Console in your browser (f12) and then navigate to Application → Local Storage. The second item in Local Storage should display the current values that are saved.
localStorage.getItem('autoFillValues');
If you have no autoFillValues stored after Indexing then the browser may be preventing this. You can try to use another browser or review with your browser vendor.