To detect possible reasons for the drop in traffic on a website, I would recommend following these steps:
1. Check traffic statistics: It is important to examine website traffic metrics through tools like Google Analytics. See if there has been a sudden or gradual decrease in visits, and what type of traffic has been affected, be it organic, direct, referral, or search.
2. Analyze recent changes: It is important to note if changes have been made to the website recently. This may include design updates, URL structure changes, keyword changes, or new feature implementations. These changes could impact the visibility and positioning of the site in search engines.