Data Director created empty objects on run automatically on new data

[CRISTA-AF]

I have created a dataport to check Data Quality via an HTML progress bar as in tutorial:
https://www.youtube.com/watch?v=M1VVmpTjB_I&list=PL4-QRNfdsdKIfzQIP-c9hRruXf0r48fjt&index=8
So that newly created or modified objects are publish/unpublish based on data quality, run automatically on new data was enabled.

The issue is that thousands of objects of the class are being created automatically, these objects are empty except for the data quality progress bar.

I'd appreciate any clues as to why this is happening.

[BlackbitDevs]

Have you configured a key field in attribute mapping? I see that you have mapped key (which in attribute mapping is named Object name to prevent misconception with key fields which are used for retrieving existing objects) but have you really mapped a raw data field there or maybe forgot to return something in its callback function? Because it seems to be empty - I only see it from the version note where only the suffixes in case of duplicate full paths get shown.

If this is not the cause, please attach dataport definition (Right-click dataport -> Export).