Add User Tod private Channel on Android


i have recently installed a RC-Instance on Ubuntu 18.04 via snap.I’m new to I tested the iOS app and could not find any problems. But with the Android app, I can not add users to an existing (private) channel. Unlike the iOS app, the “plus” button is missing in the user overview. Also, I can not join a public channel because I can not find the “Join” button in the Android app.

Is this a normal behavior of the Android app?

Thank, you!