It doesn't seem to work in min. price and max. price setting in the payment meth

Hello,

Please, provide us these elements in order to better understand the context :
1. An Url link to your website
2. Screenshot of the relative Shipping Method settings

Now, supposing the min/max are properly configured, what you describe is often caused by the fact you didn't set a weight in the products and that the "include virtual products" setting is turned off in the shipping method.

Note : If for a reason or another you can't directly provide these elements here, use our Contact us form, and add an Url link to this topic.
Regards