Hummingbird Breaking Banner

Hi, I have been using Hummingbird for some time now and it has been great. I just put it on one of my sites. as soon as I activate hummingbird and start running the test it breaks the banner on my front page and it just disappears. This happens without switching any of the CSS or js files around. I'd really like to use this for the render blocking purposes.
Thank you for looking into this.