The site has been indexed, but some pages do not appear in searches at all. It appears when you "Request Indexing" in Search Console, but disappears again after a week or two. There is no manual penalty. What could be the reason? website and problematic pages: https://avto-servis.az/ehtiyat-hisseleri
So many reasons- Google de-indexing your pages due to low-quality or duplicate content, technical issues, or incorrect noindex/robots settings