Issue with Data Not Appending to Warehouse Table in Pipeline

Hello ronan_b6 

The dataflow might execute before the upstream notebook completes writing cleaned data to the lakehouse, resulting in an empty or outdated source

In the dataflow’s warehouse destination settings, ensure Append is explicitly selected (not defaulting to Replace).
2. Avoid using “Auto create table,” which can reset configurations.

Rebuild the warehouse connection or clear cached credentials.
• Add a 1–2 minute delay after the notebook to allow metadata synchronization.

Please see if some of the suggestions are helpful