There are several reasons why pages suddenly lose rankings even when you did not change anything on your site. I have dealt with this multiple times across my travel websites, so here is what I have learned:
1. Google algorithm updates - This is the most common cause. Google rolls out core updates several times a year, and sometimes your pages get caught in the crossfire. Check Google Search Status Dashboard or follow SEO news sources to see if an update coincided with your ranking drop.
2. Competitors improved their content - You might not have changed anything, but your competitors did. Someone published a more comprehensive, more recent, or better-optimized page on the same topic and Google decided to rank them higher.
3. Search intent shift - Google sometimes reinterprets what users mean when they search for a keyword. A query that used to show informational results might start showing commercial results, or vice versa. If your page type no longer matches the new intent, it drops.
4. Content freshness decay - Some queries are time-sensitive. If your content has not been updated in a while and competitors have fresher information, Google will favor the newer content.
5. Technical issues you might not notice - Check for sudden increases in page load time, mobile usability errors, or crawl errors in Google Search Console. Sometimes a plugin update or server change causes problems you do not immediately see.
6. Lost backlinks - Use Ahrefs or a similar tool to check if any significant backlinks pointing to that page were recently removed or the linking sites went down.
My recovery process: first check GSC for any manual actions or security issues. Then compare the timing with known algorithm updates. Then audit the page against the current top-ranking competitors. Usually the fix becomes obvious once you compare your content side by side with what is currently ranking.