This is happening because the waterfall continues running even after finding an email when that email fails validation.
When an email waterfall runs, it checks multiple providers sequentially. If a provider finds an email but it fails validation (deemed invalid), the waterfall automatically moves to the next provider to try finding a valid email.
The final validated emails only appear in the last column of your table when they pass validation checks. If no valid email is found after checking all providers, no email will appear in the final column.
To better understand what's happening, you can unhide the validation columns (they're hidden by default). This will show you exactly why certain emails aren't making it to the final column.
Hi Tim,
Thank you for reaching out to the support team. Can you send me a link to the table in question and I can take a look!
I look forward to your response!