Describe the bug

I have the following issue together with wpbakery / js composer. In the backend editor, the Tiny MCE keeps ‘growing’ once it is opened until the window is filled and it keeps growing. with every click in the text field. This is not the case in other basic themes.

You can see the issue here:
https://www.youtube.com/watch?v=nxTkQ7aaA_c