Zaps get stuck in a “loop” when they run over and over again from a single trigger event. Zap loops can occur if you have two Zaps that trigger each other, or a single Zap performs an action that is identical to the event it is triggered from.
Zap 1: When a new contact is added to Salesforce, create a new contact in Google Contacts.
Zap 2: When a new contact is added to Google Contacts, create a new contact in Salesforce.
This causes a Zap loop as the first Zap triggers the second Zap, which then triggers the first Zap, and so on.
Taking the steps in this article will prevent a non-stop loop from occurring in your Zaps. It will not enable two objects to sync or update across different apps. Learn more about Zapier’s support for two-way syncing.