In terms of logically what the troublesome query could be similar to portions of the query from sheet 1 in my previous message. My guesstimate is as follows:

SELECT secondEmailAddress FROM `default`.`salesforce_export_1_explorium_15sept2022` `salesforce_export_1_explorium_15sept2022`

JOIN `default`.`salesforce_export_1_explorium_15sept2022_professional_email_validation` `salesforce_export_1_explorium_15sept2022_professional_email_val` ON (`salesforce_export_1_explorium_15sept2022`.`Professional_email` = `salesforce_export_1_explorium_15sept2022_professional_email_val`.`Email`)

WHERE (CASE WHEN ((`salesforce_export_1_explorium_15sept2022_professional_email_val`.`Status` IN ('valid')) OR (`salesforce_export_1_explorium_15sept2022_professional_email_val`.`Status` IS NULL)) THEN false ELSE true END) AND secondEmailAddress IS NOT null

only 447 records(email addresses) were returned. This is all I can logically tell you about the query, but as for the specific query itself I still don't have it.