Flat rate hourly pay type

Hello,

We setup  paytypes that we are using temporarily to pay an additional hourly rate to certain employees.

The base one is to pay $1.25 per hour (we have an OT ones too), managers enter the paycode on the employee timecard and the hours worked for it (in addition their normal hours and type).

Largely it has worked as designed, but we have an issue when union employees go through a step progression (which we have set to automatic).

If the employee steps during the pre-payroll, it is paying the new paytype at their hourly rate, rather than the $1.25 hour.  I would assume this is because of in P050002A (Time entry MBF), 1.Pay Rates, we have 2. Highest Rate 1=Use highest rate (1. Has use union rate).