On non-experimental exports any animation that changes the render scale of a hidden by default cube will force the cube to be visible.
The attached zip file contains the project file in which i discovered this weird behavior, it is just a some cubes and a single toggle animation.
komarusoundengine2.zip
Bug was found on CPM 0.6.19a Forge version 47.3.7 1.20.1

Duplicate of #323

Any cube animation will force the visibility on the normal export option.
The normal export option must animate all of the cube properties every frame, it's a limitation of the old system. Due to a bug the visibility is always animated to 'show' unless you have visibility changes during the animation.