Pivot chart X axis labels not aligned to the corresponding vertical bars

You currently have your data series formatted to be partially separated. Select one of the data series and try formatting to be fully overlapped. That should move both data series so they occupy the same, central position over each category label.

Thank you. I have tried but no luck. I don't know how to follow your steps. I am so sorry, If you don't mind, would you show me step by step?

I may not be the best one to walk you through the steps, since my older version of Excel might use a different interface. Basically:

1) Select either data series (I selected one of the orange bars).
2) Bring up the "format data series" dialog/pane (see if this help file helps find the formatting options for the data series: https://support.microsoft.com/en-us/...1-9d3ed9f0dbf0 )
3) Find the "Series Overlap" setting and change it to "full overlap" or "+100%" or whatever the equivalent is in your version of Excel.

I will see if someone more familiar with the O365 UI can provide more details on where and how to find these options.