Can contingent workers be identified in an approval flow?

Summary:

System does not generate a flow when the approver is a contingent worker.

Content (please ensure you mask any confidential information):

We have an approval flow that uses "Job-Level-Based Line Manager Hierarchy" in one of the steps, but it is not working when the approver is a Contingent Worker. Is there any restriction? Or should this step work for all types of people?

Employee requests
Approver 1 - Immediate Manager
Approver 2 - By Role
Approver 3 - Manager with job level 80 (In this step the system does not generate a flow when the approver is a contingent worker)
Approver 4 - By Role