By default, the app adds the bundle items to the bundle order via order editing, which may result in the shipping weight being doubled.
There are two ways to prevent double shipping weights:
1. You can set the dummy product weight to 0 by enabling the “Set dummy bundle product weights to zero” setting in Bundle Kit > Settings
2. You can enable the "Enable Cart Transform" setting in Bundle Kit > Settings. This option adds the bundle items directly at checkout (not the cart) and excludes the dummy product from the Shopify order.
You can find more details here: Enable Cart Transform