Tax account defaulting to single account after complete in fusion receivables

Summary:

we have the billing lines coming from Contracts/Projects module to receivables. Before the invoice gets complete in receivables we noticed the tax accounts are picked as required ,after the invoice is getting completed it defaults to one account and accounting happens for the same. we need the tax account as per the requirement. while we create invoice manually in AR module the details are split as desired. Please help us in solving the issue.

We have defined two different tax accounts in fusion tax and calculation of tax happens in vertex.

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