WMS Picking order

How do I get tasks to dispatch on the MWA in location, then item order? Right now our tasks are in locator order (controlled by the picking order in the stock locators) but the items come out in seemingly random order.

We know we could somewhat control this by how we assign priority on the warehouse control board, but feel there should be a set up we are missing. I've tried different variations of the pick slip grouping rule but nothing will put the items in order.

For example: Locator 1-A-1, items in release are a, b, c, d

Items dispatched order : b, a, c, d, a , d, b