The comment describing UClass::HasProperty() indicates that it checks to see if a specified property exists in a class, or a parent of that class. However, when a property that exists in a child of that class is passed in, HasProperty() still returns true.
A message is displayed on the screen indicating that AActor contains MyComp.
A message is displayed on the screen indicating that AActor does not contain MyComp.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-67859 in the post.