NoIndex/NoFollow in Code

Please double check that the “Discourage search engines from indexing this site” item is unchecked in your Reading Settings.

It’s possible some sort of sever side caching is serving stale page data, you should flush any server side caching that might be in effect.

Another possibility is your theme or one of your plugins is responsible. As a test, try switching to one of the Twenty* default themes and deactivating all plugins. You presumably have flushed any server side caches at this point. Also clear your browser’s cache for good measure. When you reload the page with a default theme and no plugins, your page will no longer look right, but the offending meta tag will be gone.

Isolate the responsible module by restoring your normal theme and plugins, one at a time, checking for the meta tag after each. When it reappears, the last activated module would be the cause. There ought to be a setting somewhere in that module’s settings letting you disable the meta tag. If you cannot find it, I recommend asking for assistance in that module’s dedicated support channel.