The most likely cause is a DAW feature called 'Dynamic Plugin Processing'.
When a plugin has no live audio input assigned to the channel it is inserted on the DAW will usually disable the plugin to save on CPU usage. In Pro Tools this can be disabled in the playback engine settings.
For other DAWs it is best to assign an input to the auxiliary channel the MINIBUS Receiver is inserted. If the MINIBUS Receiver is inserted on an audio track, you will need to enable input monitoring to enable the plugin.