1. Crawling Issues: Googlebot might not be able to crawl your pages due to various reasons such as server errors, blocked resources, or incorrect configurations in your robots.txt file.
2. Content Quality: Pages with low-quality content or duplicate content might be skipped by Google during the indexing process.
3. Noindex Tags: If your page has a “noindex” tag, Google will not index it.
4. Redirects: Pages that have redirects (301, 302) might not get indexed if not handled properly. This is particularly relevant for the “Page with redirect” error in Google Search Console.