Popup design is broken with Asset

I'm using CkEditor with asset and there is a problem with the iframe embed in the popup. I don't know if it's an Asset bug or an CKEditor one. I test on a scratch version and the problem is still there.

The problem seems to be on the div that has the class "cke_asset_frame_68" and id "cke_67_uiElement"

If anyone know how to resolve this issue.

Thk!