The increase in Gross Pay is most likely due to an ‘Ongoing holiday payment'. This is being added to the gross pay because you have assigned your employee to an Option 2 Holiday Scheme i.e. one which pays and clears accrued holiday pay each period.
If this holiday scheme is not suitable for your employee(s) you can view other available schemes and/or set up your own holiday schemes by going to Employer/Setup in the Tasking Zone, then selecting Chart of Setup, then clicking on the Holiday Scheme link under Holiday Setup.
Road Map - Holiday Scheme Setup
Then, to assign a more appropriate holiday scheme to each of your employees, go to Employee in the Tasking Zone, then select View/Edit Employee Details, View/Edit, View /Edit Employment Details, then click on Edit, change the assigned Holiday Scheme and click on Save.
Employer/Setup -> Chart of Setup -> Holiday Setup -> Holiday Scheme Link -> Edit button -> Save button
( 'Employer/Setup' is the button positioned in the tasking zone menu at the
top. It is the first button from the left)