When using a Vertical/Horizontal layout group that changes sizes of children as a parent of a Responsive Container hierarchy, I get really strange behavior and different results depending upon if I am running in editor or running standalone build. Also, sometimes the issue seems to be fixed, until I close Unity and restart it, then the issue comes back. I definitely see NaN when things are messed up.
We use a lot of prefab objects so that we can line up the information we are trying to display in different orientations on the screen depending upon project needs. e.g. Horizontally across the top of the screen, or vertically down the side of the screen.
Originally, there were situations where we couldn't duplicate the container behavior with just Responsive UI components. However, we now have more experience with Responsive UI and I am in the process of trying to remove the layout groups and switch to use Responsive components.
But it may be worth looking into and maybe adding a detection for the situation and issuing a warning or something.