Why isn't my weight-based flat rate shipping setup working correctly?

I am trying to set up shipping on flat rate, based on weight of items. I have no product specific shipping, no applications that modify shipping, and only have one shipping zone. No other factors apply, just a failure for general shipping rates to apply correctly.

I sell a variety of sized items and have set weigh limits based on their products pages listed weights, with only one variant on each page. No matter how many times i adjust or try to fix the shipping rates, General shipping only selects one option for everything to be shipped.

If i remove the weight maximum, then it always applies the cheapest price, So i know it sees the weight as correct, it just doesnt apply correctly.

Example:

Item one is 2g and is shipped at 99p.

item two is 21g and is shipped at 1.45p

I want to sell 10 of item 1 before before the price of shipping is the same as item two. To do so I set a weight limit for item one shipping weight to 20g, so it should stop applying the 99p shipping rate after 10 of item one has been purchased. Instead, it always applies Item two shipping rate, no matter what.

Please help

Hi @JUSTIN0

I think this setup will work efficiently if you configure shipping conditions based on product quantity. For example till product quantity 10 the shipping charge will be 99p & over that 1.25p. You can easily achieve this with Shopify Multi Carrier Shipping Label App. If you are looking for something similar or want to know more about it, I will be happy to help!