Why did the distribution line change when the invoice posted?

Summary: An invoice was create and it contained a specific general ledger distribution combination. However, when the invoice posted and was accounted for the combination changed and we had to correct it. We need to learn why it changed upon posting. This invoice was associated with a Project. We are thinking the GL string changed at posting because of this.

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Version (include the version you are using, if applicable): Oracle Fusion Cloud

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