TM charge calculation for road freight order

Dear Experts,

I'm quite new in the M world an hope that you could help me with following process:

1. I create a road freight order:

2. I create a new stage for this road freight order with 250 km:

3. I calculate the charge:

4. As I have two charge types I expect that both of them will be added together; 350 + 50:

5. But for some reason the total amount is only 50:

Does anyone have any idea, why the calculation works like this and how could i fix it?

I would appreciate every idea.

Thank you in advance and BR.