public SSL certificate on Tomcat but still have to manually trust CA certificate

[mallej]

Hello, as mentioned here untrusted root certificates installed manually on unsupervised iOS devices need to be manually trusted in Certificate Trust Settings during user-initiated enrollment.
So i obtained a publicly-trusted web server certificate from letsencrypt.org and upload the SSL certificate via Apache Tomcat settings in the JSS.
I assumed that this will stop the manual trust behavior but with no luck.
May there a technical problem or do i misunderstood the whole process?

[tuinte]

While public, your root CA may not be inherently trusted by Apple/iOS 10, in which case you'd still need to manually trust it.

Here's Apple's list of trusted root certs for iOS 10.

I don't see Let's Encrypt on there.