We tried to use the Chrome for testing and also the CardDav Sync apps for Android mobile.
For the chrome, after the sucessful login, we are prompted with Bad Request.
For the CardDav Sync apps, we have this:
20180905T034945Z I org.dmfs.carddav.authenticator.AuthenticatorActivity addressbook discovery log:
20180905T034945Z V org.dmfs.dav.Dav get principal /.well-known/carddav
App version: 0.4.21
OS version: 26
OS Info: samsung/greatltexx/greatlte:8.0.0/R16NW/N950FXXU4CRGA:user/release-keys
Date: Wed Sep 05 11:4