Select multiple automation points which are at the bottom of a lane (negative infinity). The white box appears, but if you try to drag the box upwards? Nothing happens.
Confirmed here in Cubase 8.0.30. It seems that when editing automation points, ‘Move vertically’ scales instead of moves. Midi channels operate as expected, but audio channels (including FX, groups, instruments etc.) don’t. I can’t imagine this is by design…