When creating a new issue this WYSIWYG editor shows up, unfortunately it always thumbnails copy/paste screenshots....

When editing this editor shows up, it is not the same like on create and has also a different behavior:

For me its the better editor because it supports direct copy/paste insertion of fullsize screenshots (without thumbnailing them). This is exactly what we miss a lot when creating new issues.
I want the WYSIWYG to be the same editor everywhere. How to set it up?