Thank you for reaching out to us on this.
Usually, transient means when an object is imported to the connector space that has the same distinguished name attribute as an existing connector space object but a different anchor attribute, the existing connector space object is marked as transient. If more objects are imported with the same distinguished name and a different anchor attribute, each one will become transient. Only the last object imported with that distinguished name will be non-transient. Objects marked as transient remain in the connector space until they are updated with a new distinguished name, or are deleted from the connector space during a full import. In this case, AD connect sync engine assumes that because the object does not exist in the connected data source, it was deleted, therefore it will be deleted in the connector space.
In your case you can initiate a full sync through PowerShell so that all the sync cycles get's completed in an order. This will fix the issue.
Hope this answered your question.
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