hi, yes it's all working as supposed to, not a bug nor reason to panic here :)
as a rule, whole midi files (SMFs) can only get dropped into either of the following:
a) to the main tracks view blank area, for which all tracks will be imported on a per Mtrk/channel basis (depending whether its a format 0 or 1);
b) to the MIDI Files window (usually on the right pane, if visible); from there you can choose to drag one track (Mtrk) or one single channel sub-item and only these may be made available to drop correctly into an existing MIDI track;
hi, yes it's all working as supposed to, not a bug nor reason to panic here :)
as a rule, whole midi files (SMFs) can only get dropped into either of the following:
a) to the main tracks view blank area, for which all tracks will be imported on a per Mtrk/channel basis (depending whether its a format 0 or 1);
b) to the MIDI Files window (usually on the right pane, if visible); from there you can choose to drag one track (Mtrk) or one single channel sub-item and only these may be made available to drop correctly into an existing MIDI track;
hth.
cheers