Participant cannot be added as the Manage Participant Feedback task status is not eligible HDL error

Summary:

Content (please ensure you mask any confidential information):

We've been trying to load a participant to the employee's participant feedback task via HDL. However, we always receive the same error: Participant cannot be added as the Manage Participant Feedback task status is not eligible. We are experiencing this error in our TEST environment, but it works in our DEV environment - even with having the same setup.

Here's the HDL that we used:
METADATA|PerfDocComplete|AssignmentNumber|CustomaryName|Operation
MERGE|PerfDocComplete|E10000308|Leistungskompass 2024|ORA_ADD_PARTICIPANT
METADATA|Participant|AssignmentNumber|CustomaryName|ParticipantRoleTypeCode|ParticipantPersonNumber|SendRequest|DueDate|Message
MERGE|Participant|E10000308|Leistungskompass 2024|Mitarbeiter|70000352|Y|2024/07/24|Hallo,