I spent an afternoon working out why 22 of 23 pages on a site I run were sitting in Google Search Console as "Discovered — currently not indexed."
The answer turned out to be mostly "nobody links to you, you're a new domain, get in line." That part isn't interesting.
What was interesting is what I found on the way there: every prerendered page on the site was shipping with three <title> elements, two <link rel="canonical"> tags, and two <meta name="robots"> tags. There was already code in the build whose entire job was to remove those duplicates. It ran on every page. It was doing nothing.
Here's why, because I think this bites anyone doing React 19 + prerendering.
The setup
