One of the biggest pay issues is people who cross train not getting paid for their new work center. If I remember correctly over half your shifts have to be in that new work center for your base pay to change. So someone who works 4 days in softlines and only one day in Starbucks will stay at the softlines rate.
Above post is great advice, ask your TL and they will likely refer you to HR. Its an easy fix for us to change your pay rate.