Issue
If https://yourdomain.com works but https://www.yourdomain.com fails to load securely, it’s likely because the SSL certificate was issued for the root domain only.
Solution
When issuing or renewing your SSL, ensure both versions — yourdomain.com and www.yourdomain.com — are included. Alternatively, redirect all “www” traffic to the secure non-www version by adding a redirect rule in .htaccess.
Tip
Keep your domain structure consistent. Whether you choose “www” or not, redirect all traffic to a single secure version for better SEO and user trust.