I have indexed my site to google and get error “No: ‘noindex’ detected in ‘X-Robots-Tag’”. How to remove this header tag?

Why only some of the pages (one example) are facing No: 'noindex' detected in 'X-Robots-Tag' http header error by Google Search Console?

If my search/index settings would prohitbit google bot, then they should get ‘No Access’ error on all pages. Why only some of the pages are returning the above error?