Collision of fixed exchange rate in purchase orders &1 and &2

What causes this issue?

You tried to assign the purchase order &V1& with a fixed currency key
and exchange rate. This collides with purchase order &V2&, which has a
different fixed currency or exchange rate, and which has already been
assigned.

System Response

It is not possible to assign both of these purchase orders.

How to fix this error?

Split the invoice into different parts, ensuring that each part has the
same currency and exchange rate values.

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