To troubleshoot cost discrepancies between GCP and CloudHealth, please run the following BigQuery SQL to retrieve the raw billing data for comparison.
You can use the below SQL to get the cost details from GCP BigQuery.
SELECT
billing_account_id,
Invoice.month,
SUM(cost) AS total_cost
FROM
Project_ID.Dataset.Table where cost_type in ('regular')
GROUP BY
billing_account_id,Invoice.month
ORDER BY
Invoice.month