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

使用連結的 CodePen 重現此不一致，在時間週期軸上將 scattermode 設為 "group"，並將 xperiodalignment 設為 "start" 或 "end"。追蹤這些屬性的 scatter 和 hover 處理，新增涵蓋偏移標記的回歸測試，並確認 hover 標籤與 x 軸值一致。