SOAP trigger value not accessible inside Integration

Summary:

I have an App driven integration with SOAP trigger where value is received using a soap payload. When i try to assign that value anywhere throughout the integration i receive below error.

value is invalid.

Xpath expression associated with <from> in copy assign activity is invalid.

There is an user error that results in missing element value(s) in the xpath query.

I checked the receiving payload and the value is received through payload.

I have checked thoroughly and the value is correctly mapped.

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