With the recent reduction of the sales taxes in Germany due to the effects of the Corona Pandemic, the introduction of new sales tax rates for the period between July 2020 to the end of the year have given rise in Dynamics AX to determining the correct tax rates in given circumstances.
This problem can be observed, when:

1. in the General Ledger parameter / Sales tax the field "Calculation data type" has been set to "Delivery date".
2. the customer delivers the goods using partial deliveries in differing tax rate periods, posted against one sales line.

Dynamics AX determines the delivery date using the sales line and not the individual item postings, where the correct information may be found.