The node "Get Curve Value" does not appear to return values as expected during PIE. When using the command "Watch Value" it shows up as 0.0 during PIE.
Result: The Value shown via the Watch value command will show up as 0.0
Expected: This would show the current value of the curve for the animation being used
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-74663 in the post.