Nuxt child transitions not working in some cases

Question

I have an app with a simple child/grandchild 2-layer nesting and I'm trying to do transitions on both layers of nuxt-child(ren). Mysteriously, the transition works fine on the grandchild but for some reason doesnt work on the child even though its the same transition. I can inspect in the inspector and verify that its applying the classes correctly. What ends up happening is that instead of a smooth transition for 500ms, it just pauses for 500ms and renders the child page.

Here's the simple repo demonstrating the issue. Here's the code sandbox with a deployed app.

Here's how I'm doing transitions:

Template:

    <transition name="jade" mode="out-in">
      <nuxt-child></nuxt-child>
    </transition>

Style:

.jade-enter-active {
  transition: all .3s ease;
}
.jade-leave-active {
  transition: all .8s cubic-bezier(1.0, 0.5, 0.8, 1.0);
}
.jade-enter, .jade-leave-to
{
  transform: translateX(10px);
  opacity: 0;
}