Dim Table Returns Null On Merge Where ID is Expected.

Hi UncleLewis ,
Thanks for using Microsoft Fabric Community.
Just wanted to check if your query is resolved and the helpful suggestions from danextian and Sonalika were useful to resolve your query.
If you are still experiencing issues, please consider the following:

As mentioned by danextian  and Sonalika , handling invisible characters, case, and ensuring proper step order are critical.

In addition to that, a few more things to check:

• If you're using an Index column after deduplication, make sure you're not merging on a version of the table before the index was created or deduplicated. You can verify this by stepping through the Applied Steps and ensuring the merge uses the final version of the dimension table.

• Sometimes, Power BI shows merged results as null due to cached previews, especially after changes. Try refreshing the preview or doing a full refresh of the data model.

• If you've merged but also have a relationship between the same tables in the model, it might interfere with expected results when expanding. Temporarily remove any relationship and re-test the merge logic in Power Query alone.

Hope this helps. Please reach out for further assistance.

Please consider marking the helpful reply as Accepted Solution to assist others with similar issues.