There was an error in the wording.
In my experiment, there were two approvers.
For the second approver to perform an Expire on an item approved by the first approver, they needed to be in the System Admin Group.
These two approvers are registered in PVP.
According to the customer's understanding, in the previous version(4.1.3), there were two approvers.
The second approver could perform an Expire on an item approved by the first approver even if they were not set in the System Admin Group.
The customer believes this behavior may be a bug.