Hmmm. Pretty funky. Looks like in one case you had AutoZoom off and then double clicked a track header to maximize it in the window. In that case the split bar between busses and tracks will modify the size of the maximized track. This much is as intended.
Then you scroll away from that track, but moving the split bar continues to change the track height of that one track you had maximized. Then you turn on AutoZoom and move the split bar... more of the same.
In other words, the point at which the split bar controls the track height should be released is poorly defined in the app causing goofy behavior.
Yes? - same is true on the bus pane.