payment issues Fiverr Deduction

[zainbajwaa]

I've completed 3 projects on Fiverr, 1st is for 5$, 2nd is for 7$ and 3rd is 8$. As you can see in the attached picture 1st order's payment is 4$ which is okay (deducted 1$=20%) , 2nd order's payment is 2.60$, 3rd order's payment is 1.60$ respectively which I don't understand. Please help.