I use a mac mini with firefox

The menu bar on the right hand corner and Add Ons Close immediately when trying to open when the window is minimized. From research I thought it might be extensions. I checked and everything is fine. I also tried to refresh Firefox and that did not work. I did notice when I put the window to full view everything works fine. I am wondering why it does not work properly when the window is minimized to a smaller view. Your help would be appreciated.