Position of hover label darts around with multiple data series

There seems to be a bug with what the black hover info tooltip does when a scatterplot chart has multiple series. With just 1 series of data it works fine, as expected.

With multiple series it darts around randomly, although it shows the same value. All additional data series have

hoverinfo: "none"

where the original series has

hoverinfo: "y"

With the plot having

hovermode: "y"

(broken version)


I have found that a workaround is to change hoverinfo: “none” to hoverinfo: “skip”, but to me this seems like a workaround rather than a solution.