Feedback Message appear awkwardly in the Preparation

Feedback Message appear awkwardly in the Preparation

  
Hello,

When I put Feedback Message Action in the Preparation, it appear awkwardly, it looks like appear double-time.
I am using London theme.
When I using london_fixed, it does not appear double-time, but it does not disappear smartly when clicked close button.

I temporaly using alert of the javascript, but anyone can found way to avoid the issue?