You are doing something wrong, really.
Perhaps it is in your cache. Or memcached is not fully flushed. I just tested it on two installations without a problem. I cannot help you then. :/
Set it to “NO”, run down, up -d and clean your browser cache.
In my tests it was not necessary to do that though.
Perhaps, even worse, another instance of SOGo is running as container.
It is always a fresh installation, it does not mean it is messed up. 🙂