This article covers 

Data validation step shows only 1000 customers while the customer has more than 1000 records in Chargebee 

We get the error during data validation- We could not find any records in Chargebee with the Chargebee Customer Field you have selected

Summary

1. The initial validation step is done for only the first 1000 records. Once the Initial Sync is run, data can be validated, and then all records can be synced using "Sync All Records".

2. We could not find any records in Chargebee with the Chargebee Customer Field you have selected - This error comes up when we have a custom field in Chargebee mapped to an intercom field as part of sync preferences and there are no customer records in Chargebee which have value for that custom field. As a solution, you would need to add value to the custom field.