Group tracks can only be adjusted in height individually.The height of tracks can be adjusted. This is particularly helpful when it comes to accurate editing of sound cuts or dissolves.
Grab the lower edge of the track head and drag it to the desired height.
The default height can be resumed by right-clicking the track head and choosing Default size.
You can mark several tracks to jointly alter the height of all these tracks . .... See also Marking tracks.
Group tracks can only be adjusted in height individually.