The issue you are experiencing with the Lookup activity in Azure Data Factory may be related to the differences between the new Snowflake connector and the Snowflake (legacy) connector. According to the documentation, the Snowflake connector supports BigDecimal in the Lookup activity, while the Snowflake (legacy) connector does not. It's possible that the new connector is returning the value as a BigDecimal, while the legacy connector returned it as a string. You can try converting the returned value to the desired format using a dynamic expression in the pipeline.
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