How do you type into the Help Search Field?

I am running Version: 5.2.0.4 on OS X El Capitan Version 10.11.6. About one third of the time I select “Help” in the menu bar and the help screen comes us, I am not able to type anything in the “Search Term” field even though I have put the cursor in the field and clicked the left mouse button 2 or 3 times. Often, but not always, if I type the search term into a text document, I can copy and paste it into the “Search Term” field. Once I have managed this, I then seem to be able to edit what I have typed in.

I will greatly appreciate an information about what I am doing wrong.

Thanks,

Jerry