A trace's 1-based position among the groups plotly drew into its panel's
g.boxlayer.
Box and candlestick share that layer, so the count has to span both: a
candlestick declared first takes the first group, and a walk over boxes
alone would hand the box that follows the candlestick's group.
A trace's 1-based position among the groups plotly drew into its panel's
g.boxlayer.Box and candlestick share that layer, so the count has to span both: a candlestick declared first takes the first group, and a walk over boxes alone would hand the box that follows the candlestick's group.