An internal error occurs when a recruiting user moves more than 20 candidates from Forwarded status to Default (New Application) status or performs Add to Requisition for more than 20 candidates.
SAP SuccessFactors Recruiting Management
The issue is happening when the user has different username and userId.
This issue is corrected in 1H 2022 (b2205) release by RCM-102337
RCM-102337 , KBA , LOD-SF-RCM-APP , Applicants and Job Applications , Known Error