Moving a component in a child blueprint causes the parent blueprint to become dirty and requires it to be recompiled.
*Regression (No) issue (does) occur in 4.10.4
Moving the cube causes the parent blueprint to become dirty and need to be recompiled
The cube is moved and the child blueprint must be recompiled. The parent blueprint is unaffected.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-30473 in the post.