I’m having problems with the Youtube embed. It’s too big (more long than wide) on the page. When I change the theme to the wordpress 2015 theme, this doesn’t happen so I’m thinking it is a GeneratePress problem. I have also tried to install the responsive column widgets theme but that doesn’t make it it any better.
GP tells WordPress the width of your content area so the auto embed of galleries, videos etc.. will fill the area.
To avoid this, simply choose your own video size when getting the embed code from YouTube – this will guarantee the video is the exact size you need it to be.