It used to be that in a project, each track would have a + that lets you add a track. Now in MSP 2025 - the tracks don't have the + or X symbols, and I can't figure out how to add a track between 2 existing tracks? How do you now do that?
Further to what Jeff indicated, you must have opened the dropdown and changed the Track height to Small. Click on the second button from the right - maximize - to get the buttons back on a track. Then open the dropdown and change the Track height to Default to get the buttons on all track, if you wish.