We have subdomains for czech, chinese, german, french, italian and we saw that the domain directory has changed without our permission and we determine that cn.nasiol.com and cz.nasiol.com are not working on Cloudflare.
Please kindly guide us for solution.
Your server probably does not serve them on HTTPS. Check that their server configuration matches the one of your other working hosts.
Thank you. They offer me to change dns from Cloudflare to their hosting. Is there any other way that you can suggest to us?
DNS is not related to that, you simply need to make sure that all your virtual hosts are properly configured for HTTPS, right now only some seem to be configured.
We did not activate ssl on server. Is there a way to handle this problem on Cloudflare?
You should definitely activate if you want to use HTTPS and you must have activated it already for the Italian version for example.
Bottom line is, the configuration should be identical (except for where they should not ) and yes, do enable SSL everywhere.
Your hosting provider hosting your DNS wouldn’t solve this issue, so they aren’t being terribly helpful. You could use page rules to set flexible SSL for some subdomains, but @sandro’s suggestion your hosting provider configure the virtual servers the same way for each host is probably the better way to go.