There are instances where the talent pool count is not mismatching the actual candidate in the talent pool.
SAP SuccessFactors Recruiting Management
The discrepancy in count is due to candidate privacy or some of the candidates are already deleted or inactive. Also the data is being retrieved from the database instead of the SOLR server causing data to be asynchronized.
There is already a permanent enhancement that is being worked by the Engineering team to address the issue. We will update this KBA on the progress. To get notification on the update, you can add this KBA as your favorite.
You cannot view some candidates in this talent pool due to their candidate profile visibility settings or inactivity, RCM-96197 , KBA , LOD-SF-RCM-CRM , Candidate Relationship Management , Product Enhancement