The text in the window says “track height” but it is referring to “stack height”.
Open the set stack height window by clicking the button in the toolbar (with one or more annotation tracks selected) or by right clicking an annotation track and selecting “set stack height."
The text in the window currently reads: "Enter a new maximum track height, 0 for unlimited".
The text should read: "Enter a new maximum stack height, 0 for unlimited"
Track height and stack height are distinct concept in IGB.