Are CAs that are manually trusted in Android, not trusted when connecting to Confluence Server?

[El-ad Blech]

I can't seem to find a definitive answer, but I'm unable to connect to Confluence Server 6.8 from my Android device due to an HTTPS error. The same Confluence site is available on iOS devices with no error. Both iOS and Android devices have the CA cert pushed to their trust store. Accessing Confluence from Chrome on the Android device shows a valid certificate and chain.

[El-ad Blech · Accepted solution]

I gave up trying to get the custom CA cert to be trusted, so I tried using a public LetsEncrypt certificate instead. Using the Tomcat SSL connector (rather than an Apache reverse proxy), I was not able to successfully chain the cert to the CA cert using the instructions provided by Atlassian (using keytool). "openssl s_client" would only show the server certificate, and wouldn't get the CA cert as expected.

I switched back to using an Apache reverse proxy and configured it to serve the chained LetsEncrypt cert. This caused everything to start working properly on the Android device.