noindex – What’s liable for triggering “robots-template.php” file or “wp_robots_noindex()” core operate out of it?

tl;dr: What occasion, situation or scenario can:

• Set off execution of the core wp_robots_noindex() operate (from the wp-includesrobots-template.php file) or
• Trigger including <meta identify="robots" content material="noindex" /> to each web page’s supply code

if the corresponding Discourage search engines like google and yahoo from indexing this website configuration possibility is disabled and any corresponding configuration swap from each any plugin or theme are additionally disabled?

Downside

Practically two months in the past (at precisely Wed, 6 Nov, 09:07 CET+2) Google Search Console issued me a warning electronic mail that my most visited weblog web page can’t be searched as a result of it contains noindex meta tag. For example, following URL was given:

http://onezeronull.com/?s=Setting+up+password-less

I’ve visited the above web page and within the WordPress-generated response I’ve certainly discovered the next HTML code:

<meta identify="robots" content material="noindex, observe, max-image-preview:massive" />

Evaluation

I’ve searched:

• All of the core WordPress information
• All my lively plugins
• All my themes

and located nothing. Then I’ve looked for simply elements of this string and located the next:

1. The max-image-preview:massive half is present in wp-includesrobots-template.php in wp_robots_max_image_preview_large() operate (the one occasion accross total WordPress weblog community / fileset).

2. The noindex string is present in:

• A variety of information in wp-admin folder
• 4 information of the Jetpack plugin
• Six information within the wp-includes folder, together with wp-includesrobots-template.php file once more, within the wp_robots_noindex() operate.

Each talked about onezeronull.com web page and every other web page in my total weblog community has the Discourage search engines like google and yahoo from indexing this website disabled within the Studying Settings part:

Query

If the above possibility is disabled then what else may cause including noindex half to my each web page’s supply code (supplied that it isn’t brought on by any plugin, theme or configuration possibility)?

Which core code is liable for triggering wp_robots_noindex() operate from the wp-includesrobots-template.php file and the way can I block this case (or forestall including noindex by every other that means)?

Facet downside

BTW: I’ve deliberately given the Wed, 6 Nov, 09:07 CET+2 date as a result of one other “thriller” right here for me is why the entire scenario began at precisely then:

Whereas I’ve no recorder replace to neither core WordPress nor any plugin or theme at that particular level of time.

Personal analysis

I’ve searched this website and located these two comparable questions-answers:

However discovered not options since these two offers with blocking internet crawlers utilizing both robots.txt file or X-Robots-Tag: none tag. So nothing round <meta identify="robots" content material="noindex" /> meta tag.

I’ve searched quite a lot of Web sources for this downside as nicely, but additionally discovered no clue.