Incorrect Currency being sent out during cost update(adjust shipment cost) on OTM Planned shipment

When a shipment cost is updated, the system sends the cost in a different currency than the one initially used.

Example:

A shipment is initially created with a cost of 100 USD.

The planned shipment is sent out with the cost allocation in USD, and the payload is shared with the source system.

Later, an additional cost of 20 eur is added

After this update, the planned shipment is sent again, but now

the cost allocation currency is EUR instead of USD.

I am sharing the sample payload which shows the difference.

The Expected behavior is I want the currency of the planned shipment cost to remain the initial currency (USD) in which the shipment was first sent out, regardless of any subsequent cost updates in other currencies.