Starting with 2.0.0, remote access to maxscaled protocol (maxadmin listener) has been removed in favor of domain sockets only.
This change impacts external applications such as replication-manager, that could potentially talk remotely with MaxScale.
I suggest reinstating the remote protocol, but make it admin-only. The default settings for maxscale should always go to domain sockets, and the default user (admin/mariadb) shouldn't have privileges to connect remotely. In order to connect the operator would have to create a different user with specific remote privileges.