All contacts are not synced from Zoho CRM to Campaigns

All contacts are not synced from Zoho CRM to Campaigns

The contacts that are synchronized from Zoho CRM Campaigns are lower. We Zoho contacts in 2531 and synchronization, the list of contacts in campaigns is 1791 subscribers  + 112  Canceled suscription + 58 bounces = 1,961 total . Where I can see what happens to the rest?