Help needed - Gross income is always different in every paycheque

FionaGohEmp

My employer is paying me in Semi-monthly. But the gross pay amount is always different in each pay check because he is using Wave. The difference is always few dollars to around 20 dollars for me. But my peer has her latest paycheque with almost $200 less in her gross pay. Is this normal? I always have the same gross amount and deduction for every single pay check in my previous company. Please anyone could help? I can't find any way of support from Wave.... anyone could help to answer will be highly appreciated.