This tutorial covers a possible reason for the ERR_SSL_VERSION_OR_CIPHER_MISMATCH error when seen on a subdomain.
The Cloudflare universal certificates cover
*.example.com. This means that it covers any subdomain one level above the domain you signed up with.
It will cover
subdomain.example.com, as these are one level above the root domain,
The certificate will not cover
a.b.example.com, however, as these subdomains are too deep.
You either need a $10/month dedicated certificate from Cloudflare, on which you can specify the subdomain you need to cover, or to set the record to and bypass Cloudflare altogether.
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Other great resources on this community include the Community Tips . These address best practices when configuring Cloudflare, how to fix issues you may see, and tools to troubleshoot. Also you can view Expert Tips, great posts on the community that can help users with a similar issue.
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