Batch Number is not being populated for entries that are updating existing opportunities when the batch is processed, e.g. when we are marking Pledged #Recurring Donations​ as received (opportunity stage Closed Won equivalent). It is populated fine when new opportunities are created.

I've created a workflow to copy from our former custom field for Gift Batch Number for now as our team manually enters this number when matching an opportunity (because batch defaults are overwritten by opportunity fields when selecting one to match).

Hopefully I've explained that correctly @James Browne​ ​