Ajenti V? Go to Websites > webnetvn.com > Ports > 80 > Mark "Default"  > Apply

I think it might be possible to proxy to different hosts based on port - e.g., host:443/ajenti/ and host:444/ajenti/ with the same certificate

This isn't possible, because Ajenti pages include absolute /ajenti:.* URLs.

Link's not working

Also, "128.199.176.95:8000/blog" and "128.199.176.95/blog" aren't domains. This can easily prevent NGINX from applying config changes (this will be visible in configuration checks).

I assume that k-leap.com is the website in question. Please confirm that all configuration checks are ok.

Это обычно лечится очисткой кэша в хроме.

Please post your current configuration (/etc/ajenti/vh.json file). Also make sure that all Configuration checks are ok on the Websites page.

Yes, ajenti-v-ftp-vsftpd package. However it's not recommended because some users had problems with it.