Crawler skipping first line when we enable column headings option with has headings and gave column names in comma delimited list

Hi All, We are trying to crawl a s3 file which does not have any column names. We want to add column name manually while crawling the source. We created custom classifier with proper delimiter and selected column headings option with*** has headings*** and gave column names in comma delimited list. the crawler job went fine. But in the Athena we can see first row is missing from the table but we can see that record in the file. Can anyone please help to resolve this issue.

Thanks Asif