@Ramdas, Sai Kumar - Thanks for the question and using MS Q&A platform.
This is a known limitation with Microsoft Purview:
You may checkout the MS Q&A thread - Scan BigQuery in Microsoft Purview, which addressing similar issue.
For more details, refer to Connect to and manage Google BigQuery projects in Microsoft Purview.
Hope this helps. Do let us know if you any further queries.
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