There's a drawing error on curved automation segments (slope ≠ 50%) when the left key-frame of the segment is outside the viewing area. As soon as the left key-frame of the segment moves beyond the left border of the timeline area, the curve will bend upwards, outside of the region area.

Steps to reproduce:

Create an automation region and six or seven key-frames in it with different Y values.

Change the slope of the segments between key-frames.

Zoom the region on the timeline view

Slowly drag the the timeline overview window to the right.

As each key-frame disappears beyond the left edge of the view area, its corresponding segment will be drawn incorrectly.

Note: The drawing error becomes more apparent the more the timeline view is zoomed in (smaller timeline overview window). The drawing problem doesn't affect segments with a slope of 50% (no curvature).

Chrome 73.0.3683.86 official build, 64 bits, Linux Ubuntu 18.04.2 LTS