Fail to create DraftOrder with a Discount via GraphQL Admin API

Shopify Apps
1

Our app had 2 problems related to creating Draft orders by GraphQL API:

  1. According to the Shopify Document, in DraftOrderCreate, the input field ‘appliedDiscount.amount’ is not required. However, when we tried to create a draft order, we received the message: '[{"field":["lineItems","0","appliedDiscount","amount"],"message":" Applied discount amount must be greater than 0"}].

=> Can you explain this problem? Is there any update we should know and what is the workaround for this problem?

  1. Our app is using draft-order-create mechanism so that our customers can checkout with our app discount code. Previously, when creating draft orders, we transmitted information on appliedDiscount.value and

appliedDiscount.presentmentCurrencyCode; then your system will automatically convert the value to the customers’ currency. But, recently, we’ve noticed that the system no longer worked like that.
=> Can you explain this problem? Is there any update we should know and what is the workaround for this problem?