DNS updated, SSL installed, site still shows "Not secure"

Broader than browser cache — covers OS DNS cache, browser DNS cache, and ISP DNS cache (the last one users can't control; it clears only when the record's TTL expires). Clear OS DNS cache (kinsta.com guide) and browser DNS cache (torguard.net guide). Note: this article links to a dead Help Scout-internal URL that needs replacing during migration. If still unresolved, try a different network/WiFi.