My users in Turkey complains about a SSL 526 error message

Hi,

I have some users in Turkey complaining because the receive a 526 Invalid SSL server certificate.
Why this is only happening there, and how can I solve it?

Thank you.

Hey,

A 526 means there is an invalid SSL certificate.

Troubleshooting Cloudflare 5XX errors – Cloudflare Help Center

You can adjust your SSL settings to Full to work around this or make sure there is a valid certificate issued by a certificate authority.

Full (strict) - SSL/TLS encryption modes · Cloudflare SSL/TLS docs

As this only happens at one location, you can also check with the hosting provider