Mixed content happens when a page loads over https but some images, scripts or links still use http. Update those URLs.
- First make sure both addresses in Settings > General use
https://yourdomain.com. - Install Really Simple SSL, which auto-fixes most mixed content, or use Better Search Replace to replace
http://yourdomain.comwithhttps://yourdomain.comacross the database. - Check theme and widget settings for hardcoded
http://image or script URLs and update them.
Use your browser's developer console (the padlock or Console tab) to see exactly which resources are insecure. After fixing, clear LiteSpeed Cache and reload. External resources you don't control may need their own https version. Still seeing the warning? Open a ticket with the affected page URL.