Pending worker not able to convert into employee/Contingent worker

Summary:

We are trying to convert a pending worker to employee but the account is not created. I have used this process to complete them automatically.

Schedule process: Run Convert Pending Workers Automatically Process.
What could be the possible reasons for this issue?

If there is any other process to make a pending worker, please let me know.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):