Thank you for your post.
The Web Viewer must be selected for the hover to work. This is because other objects on the layout could be a button (including the Web Viewer itself) and the hover would work when those buttons are encountered.
I recommend you enter this suggestion into our Feature Requests web form at:
All entries into this web form are read by Development and Product Management where each entry is discussed and considered for future releases. I could copy your post and paste it into the web form, but there are a couple of questions asked that only you can answer.