Hover labels do not match x-axis value in scattermode "group"

We have come across an issue with scatter plots where the hover labels do not match the value of the x-axis on a (time) period axis. The problem only occurs when setting the layout.scattermode property to "group" and shifting the markers using the xperiodalignment property to "start" or "end".

Here is a codepen which demonstrates this behaviour:
https://codepen.io/apexi/pen/ExqXxKK

使用链接的 CodePen 重现该不匹配，在时间周期轴上将 scattermode 设置为 "group"，并将 xperiodalignment 设置为 "start" 或 "end"。跟踪这些属性的 scatter 和 hover 处理，添加覆盖偏移标记的回归测试，并验证 hover 标签与 x 轴值一致。