When integrating with Planning Center, you will only be able to sync one Planning Center account per Clearstream account/Subaccount (Subaccounts have their own separate integrations).
The User that authorizes the integration must use the same email address in Clearstream and Planning Center. We will only sync Lists from the Planning Center account linked to the Subscriber's email who set up the integration.
You can view which User has synced with Planning Center from Account Settings (top right corner) > Integrations > Setup.
Your Clearstream account will re-sync your Planning Center Lists every 24 hours (each night) automatically. If you need to re-sync your Lists in the middle of the day, go to Account Settings > Integrations > Planning Center > click "Run Now".