Yes, this is part of ZimaOS.
I believe this option only enables HTTPS using a system-generated self-signed certificate. It provides basic encryption but does not establish browser-trusted SSL, which is why the connection continues to show Not Secure.
I suggest treating this feature as encryption only. For fully trusted HTTPS access, a reverse proxy with a valid domain and certificate (e.g. Let’s Encrypt or Cloudflare) is required.