Site Only Appears in Omitted Results – Need Help

Recently, a prospect approached us with a website built on Laravel. When users search for a keyword like “Daikin customer care number,” their website doesn’t appear in the top 100 search results. However, if you navigate to the third search results page and click “*If you like, you can repeat the search with the omitted results included*,” their website appears. Upon further investigation, I found that out of 1,000 pages, the majority return a 502 server error, while the rest function properly. The website owner mentioned that, from a technical perspective, the Nginx server is failing to transfer or convert data to PHP, though I didn’t fully understand the specifics. I conducted several checks such as - * The site is server-side rendered * There are no canonical tags or meta robots tags * The sitemap and robots.txt file are inaccessible * There are various basic technical SEO issues present on the site To resolve this, what specific aspects should I check or communicate to the client’s developer?