[Tooltip] Bottom series are cut off

[nickofthyme]

Describe the issue

Tooltip cuts off last series in tooltip. I think this is related to single bucket charts but maybe not.

To Reproduce
Steps to reproduce the behavior:

1. Go to this story.
2. Add more series, around 10
3. See if the tooltip cuts off the last series.

Expected behaviour
Tooltip is not cut off.

Screenshots