Reveal moves page to the left

i have a reveal:

<div class="reveal" id="exampleModal1" data-reveal></div>

which i open with:

var popup = new Foundation.Reveal($("#exampleModal1"));;

The reveal appears, but the whole website (in the background) jumps to the left side.
normaly it is centered…

if i close the reveal the website jumps back.

can somebody please tell my why this happens?
i can not reproduce it with codepen…

Version is 6.6.3

P:S: google tells me that this question allready exists, but the forum doesn’t show up!


can you provide a working codepen which reproduces this? I would guess that some needed class or wrapper is missing.

Because I can not reproduce it here:

i don’t know why, but now it is working.
couldn’t reproduce it on codepen…