Automatic Comment Box setting and Highlight Feature

I am using Adobe Acrobat Reader DC (free version) on a Mac computer:

1.  How to disable automatice pop-up windows for "Add a Comment" window when I select a text?  I believe I must have inadvertently set up the feature in settings somewhere.

2.  Also, I am unable to use Highlight text feature.  The feature use to work and lately does not now.  When I select the icon in tool bar at top it responds with a marker symbol in a color and then when I move cursor over a text not highlighting  results.  How do I get the Hightllight to work?

Help!