Hello,
The weight shipping plugin allow to configure fast some price range based on the cart weight.
We created that plugin while developing the "Mondial Relay" and "Colissimo" shipping methods ; since they have a defined rates based on the weight.
So yes, the behavior you're describing is what the plugin is doing.
Regarding
I have enable it and used the same inputs as my previous shipping methods and still, I cant see the new shipping method when I order something.
I would need more details about your plugin configuration and the issue you have in the checkout.
Like that I can't tell if the problem is related to the plugin or maybe just the HikaShop configuration (or product configuration).
Regards,