Custom domain and SSL are active but site shows ERR_SSL_PROTOCOL_ERROR and Netlify URL shows 404

Support
,
1

Hello,

My custom domain is signatureedu.co.kr.

Current status:

  • Domain connected successfully
  • SSL certificate issued successfully (Let’s Encrypt)
  • HTTPS enabled in Netlify
  • Deployment completed successfully
  • index.html exists in deployment files

Problems:

  1. https://signatureedu.co.kr shows ERR_SSL_PROTOCOL_ERROR
  2. Mobile devices cannot access the site
  3. Netlify URL shows “Page not found” (404)

What I have already checked:

  • SSL certificate is active
  • Domain is listed as primary domain
  • Deployment completed without errors
  • index.html exists in the deployed files

Could someone help identify the possible cause?

Thank you.