STEPS:
1. Run Ensemble and navigate to HTMLEditor sample
2. Select all text in editor, and perform below steps repeatedly for few times to observe the issue.
2.1 Change text formats(Paragraph, Headings) from format ComboBox
2.2 Click on font size ComboBox to observe the size
2.3 If it looks good then change the font size and step goto 2.1

=> Repeat above 3 steps, after few tries, the issue should be observed at 2.2
=> Refer screenshots