I guess the problem is with FRotator::UnrotateVector - this is not a static method, which means you need to call it only from a specific object.
I think the correct wrapping is:
FVector BreakUnRotator = TryGetPawnOwnerRef->GetActorRotation().UnrotateVector(TryGetPawnOwnerRef->GetVelocity());
(I’ll think lack of compiler’s error log is just a forum bug)