dropShadow in a multi-series chart applies dropShadow to other series after hovering

[ericlighthofmann]

Description

I have a chart with two series, a bar series and a line series. I've applied dropShadow to the line series here:

dropShadow: { enabled: true, enabledOnSeries: [1], top: 5, left: 5, blur: 5, opacity: 0.2 }

After hovering over a point in the bar series to view the tooltip, the dropShadow is applied to my bar and persists until the chart is re-rendered. See the screenshot, I hovered over the first two points but did not hover over the third:

Steps to Reproduce

1. Create a multi series chart and apply dropShadow to one series.
2. Have a shared tooltip and hover over the series. See the dropShadow be applied to the other series.

Reproduction Link

Here is a minimal example - hover over a bar in the series to see the dropShadow be applied to the bar:
https://codepen.io/Eric-Hofmann/pen/MWxWeYZ

Edit:

Removing the hover state solves it, but is still probably a bug:

states: { hover: { filter: { type: 'none', } }, }