Pay Item

Has anyone had any issues where a certain pay rate item keeps going back to a different rate? I have a Level 7 pay item that "Pay Rate-Fixed Hourly Rate of" "$26.18" which is the correct rate for the award we are on. But when I am paying the employee the rate keeps reverting back to the hourly rate of $24.76 which is the rate before 1st July 2023. I paid back pay once for this employee due to this problem but have now found there are multiple times in the last 9 months that this has happened so now I am going to have to calculate all his weekly payslips and pay him back pay again. How do I stop this from happening, I spoke with MYOB once but due to the lack of the person being able to speak clear english and not having any idea what I was trying to say I stopped the conversation and just kept a check on the rate each pay and because it was staying at the proper rate I slacked off but have now found multiple pays where the old rate has been paid.