Free shipping string added to check out page

Hi, I just paid for the pro version and now I meet a problem on the check out page.

On a product without free shipping I get a “Free Shipping” string on the check out and the actual shipping price not applied to the full price.

I have another dropshipping plugin shipping plugin and I test it with the same product and don’t have this problem.

Any ideas why this Free Shipping shows and how I can remove it?!

Thanks!