1. Go to Content > Knowledge Base, and add some articles
2. Change the default site (Liferay DXP)'s welcome page to 2-column layout
3. Place "Knowledge Base Search Portlet" on a page
4. Type any words in search in Knowledge Base Search Portlet to show some articles
5. Select < button (the word "Return to Full Page Button" appears in hovering)
The back button should take me back to the originating page with the search results and keyword cleared.
The back button should take me back to the originating page with the search results, and keyword existed.