Hi Lucy,
Did you enable the feature "Leave accrual holiday corrections"?
Also, check the documentation from MS docs.
docs.microsoft.com/.../hr-leave-and-absence-types
Configure leave type rules
Set rounding options for the leave type. Options include None, Up, Down, and Nearest. You can also set rounding precision for the leave type.
Set Holiday correction for the leave type. When you select this option, Human Resources uses the number of holidays that fall on a work day to determine how to accrue time off for the leave type. For example, if Christmas Day falls on a Monday, Human Resources will subtract one day from the leave type when processing accruals.
You set holidays in the working time calendar. For more information, see Create a working time calendar
