Users stuck with pending status

We are using HDL to upload users from HRMS to HCM Cloud. This process is scheduled to run daily. However, we are encountering an issue where, in some cases, user accounts are not being created successfully. When checking via Manage User Account in Person Management, these users appear with a pending status.

This issue does not occur for all new employees — some accounts are created as expected, while others are not.To resolve the issue temporarily, we run the Send Pending LDAP Request scheduled process, which does successfully create the user accounts. However, this introduces another problem: the usernames are being automatically set to the person number, whereas we require the usernames to follow a specific syntax.