I also have the same issue, no matter if it’s wrapped in a column or not. Just having a Field Group that shows on a page with only 1 WYSIWYG field. I tried several versions of ACF Pro from 5.7.6 to 5.8.0-b3. The bug goes away if I install the Classic Editor Plugin (to remove Gutenberg) since I’m using WordPress 5.0.3, so the bug is definitely linked to Gutenberg.
Here’s another video of it in action:
https://photos.app.goo.gl/38aQH2MgNEB7T4pg8
