Issue with AppFlow importing data from S3 bucket into BigQuery

Hello,

We are experiencing a strange behavior importing data from a csv file (in a bucket on S3) to a table in BigQuery. I created a connection, and when the flow runs, it runs successfully on AWS side with no errors. But in Big Query we can only see one row when we query the table (table preview shows the right amount of rows to start with, but after a while also show 1 row).

Any idea if this is a bug in AppFlow or what I can do to fix it?

Many thanks