Why is NativeUpdateAnimation() called even in blueprint editing mode?

Picture 1
As shown above, NativeUpdateAnimation() is an overridden virual void function of class UBlasterAnimInstance, whoes parent class is UAnimInstance.

Picture 2:
BlasterAnimBP is a blueprint based on the above C++ class BlasterAnimInstance.

There is the problem, when I am editing BlasterAnimBP , it seams the C++ function NativeUpdateAnimation() is constantly being called, and it keeps printing my debug UE_LOG().

I know I can just comment my UE_LOG(), but is there anyway to stop the blueprint running C++ code in blueprint editing state?