IDoc foreground processing: JIT call already exists several times

You are currently processing an IDoc in the foreground. Several
sequenced JIT calls already exists for the external JIT call number in
question.

System Response

The values in the IDoc are accepted anyway.

How to fix this error?

You can display the existing sequenced JIT calls in a separate session
(transaction JIT3).

Error message extract from SAP system. Copyright SAP SE.