“Not secure” warning (mixed content)

If SSL is installed but the browser still says “Not secure”, the cause is usually mixed content: some images, scripts or stylesheets on the page still load over http://.

1. Open F12 → Console in your browser — “Mixed Content” warnings show which files are causing the problem.
2. Change those links to https://.
3. In WordPress, replace old links in the database with the “Better Search Replace” plugin: http://yourdomain → https://yourdomain.
4. Clear your browser cache and check again.