First responder rule not working properly

We have created an AME rule for approval using the "First Responder Wins" voting regime. However, in the actual scenario, even after the transaction is approved by one of the designated approvers, it is still being routed to the next approver in the list.

We would like to understand the following:

1. Why the approval continues to the next authority, even though "First Responder Wins" is configured.
2. How this behavior can be rectified, so that once one of the designated approvers approves the transaction, the workflow is considered complete and does not move forward for further approvals.