Fixed in Origin2020.

1.Prepare a worksheet with a few columns filled with random data
2.Select all columns and run hcluster from Statistics / Multivariate Analysis / Hierarchical Cluster Analysis
3.Click OK
4.Go to the first output sheet (Cluster1) sheet and double click on the Dendrogram plot to open up the graph
5.Go to the input sheet (Sheet1)
6.Add one column to the input sheet (Sheet1), fill with some texts
7.Click on the lock icon, select Change Parameters
8.Select the last added text column as the Observation Labels
9.Test the Data Highlighter tool again
==> Origin fails to highlight anything.