Thank you for the additional info.
If you’re calculating live rates with Shopify, they are significantly discounted from regular retail rates. It is likely that the shipping rates being provided by your dropshipping service are much higher because of this, which is why you’re seeing a difference. You will need to manually configure your shipping rates at checkout to match the rates you’re being charged by dropshipman. If Shopify doesn’t provide enough flexibility to match the rates, you may need to consider using a third-party solution to configure your checkout rates more accurately.
The rates calculated at checkout and the rates calculated when you actually ship the order are not the same - meaning the rate the customer pays at checkout doesn’t get passed on to the shipper. They’re two separate calculations, but they do need to match or be configured to be as close to each other as possible, otherwise, either you or your customer will be over-charged.
Best regards,
Ron