Please confirm the following after your first "incomplete" sync:
1. Event (and corresponding fields) has been created in Raiser's Edge
2. Metadata has been sent to Sphere
3. Raiser's Edge fields have been mapped to the relating Sphere fields
4. Sync again

If the transactions fail to show in the Connector to be processed, Chat with Support and reference this article. 
Please include examples of transactions that should have gone through the Connector, in addition to the following:
-When was your last sync?
-Do you have any error messages for your Scheduler or does it show connected to your Integration Service?
-Have any transactions for the event or form gone through in the past?
-Name of the event or form?