Grouping a midi track with an audio track- only Solo works..

Hi - I am trying to group a midi track with an audio or aux track and only the solo function works in this kind of group.

2 Midi tracks in a group do share all attributes, as 2 auxes or aux+audio or 2 audio tracks.

But when i mix a midi track with an audio or aux track, the fader and the Mute do not link.

Any thoughts or ideas? There is absolutely no mention about that anywhere in the manual or on an online discussion that i could find...?

Anyone..?