HTML formatting not getting cleared with QTextBrowser clear

If a QTextBrowser has some data with HTML formatting for the first line, Formatting is retained even after clear() is called. Adding subsequent data retains that formatting.
Steps to reproduce:
1. Execute the attached project.
2. Click Add->Refereh.

Newely added data is Bold even there is no such formatting after clearing data.
Problem is only when cursor is moved to start after adding data.