Hello Keith,

Thank you for reporting this issue, this is indeed a bug.

During the investigation, we found a potential workaround that you can try:

• Attach the OnGroupExpanded event 
• In the event handler, call the .repaint() method of the Grid: 

  function GroupExpanded(sender, args) {
      sender.repaint()
  }

This method will call the internal logic to recalculate the dimensions and apply the necessary width for the column headers to fix the alignment.

Kind regards,
Vasko
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