invalid SSL certificate for Static Web Apps

For NET::ERR_CERT_COMMON_NAME_INVALID on a custom hostname that already resolves to the Static Web App, the supported fixes are:

1. Verify that www.a-culture.com is added as a separate custom domain and is shown as secured with its own certificate binding. A hostname can validate in Azure but still fail HTTPS if the certificate does not include that exact hostname.
2. If the certificate does not cover www.a-culture.com, remove and re-add the www custom domain in the Static Web App, then complete validation again so Azure can provision a new certificate for that hostname.
3. Check DNS CAA records. Azure Static Web Apps uses DigiCert for the automatic SSL certificate. If the DNS zone restricts certificate issuers and does not allow DigiCert, validation can remain stuck or certificate issuance can fail. Add this CAA record if needed:
   • Type: CAA
   • Name: @
   • Value: 0 issue "digicert.com"
   • TTL: 300
4. After adding or correcting the CAA record, remove the custom domain, wait about 5–10 minutes, then re-add the custom domain using TXT validation and refresh until validation completes.
5. After the binding is recreated, test again from a new browser session or another device to rule out cached certificate data.

If the hostname is already correctly mapped and the certificate still presents the wrong common name after re-adding the custom domain, open an Azure support incident for certificate re-provisioning at the platform level.

References:

• Issue with creating custom domain in Static Web App - Microsoft Q&A
• Azure website problem - Microsoft Q&A
• Troubleshoot custom domain issues in Azure App Service for web apps on Windows and Linux
• Troubleshoot domain and TLS/SSL certificate problems in Azure App Service