Can't understand parenting in Animate

Hi!

I can't understand how parenting works in adobe animate.

I thought that it have to work like in After Effects. But no.

For some reason the parented parts move really weird. Sometimes I can't move or rotate it. Sometimes I made keyframe and moved the an object but it doesn't work inbetween.

For example, I have face rig. Eyeballs are parented to the face oval and pupils are parented to the eyeballs.

And if I move pupils in keyframe sometimes they don't move or rotate. I can't manipulate them.

Or sometimes I shift them to other positions in this keyframe. But keyframes inbetween don't work well.

Or if I have a layer for frame-by-frame animation parented to main layer. And when I make keyframe for new drawing, the object on this layer becomes unparented

Please explain to me how it works.

I watched some video tutorials, but there they make simple animations. They make keyframes and move all object at once. But I want to animate layers separately.