Surface modelling Fillet

Hello,

For a school excercise i have to make a car with surface modelling, its the first time i work with surface modelling so its all completely new for me.

During this excercise the next problem occurs:

I knit the 3 surfaces on the right together and after that i would like to make a fillet

When i make this fillet the next problem occurs, and i can't find the solution for it.

The fillet is getting smaller and smaller on the left side and when you zoom in (right picture) you'll see its crossed at the end point

The result should be te same as on the right side (see picture beneath)

What is going wrong here?

Kind regards,

Bryan

SolidworksParts And Features