Weight whipping doesn’t apply

Hi,

i’m experiencing a problem with the plugin: I’ve setted two different classes, one per 0<x<3 Kilos and one 3<x<10 Kilos for my client ecommerce website.
Problem is they don’t apply to the final cost, and I don’t know why.
I am following the instruction I’ve found in the screenshots, but it still doesn’t work.

Can I ask you please to check one of them and tell me if I am doing wrong or if it is due to an incompatibility with the e-commerce settings?

Thank you in advance,

Valentina