Just had the same issue last night and Larraz on the forums managed to help.
AddDynamic is a macro that calls __Internal_AddDyamic. (From what I can tell AddDynamic handles taking care of the function name string) So it will appear to not exist in your code, but if you compile it will handle it.
Also another pitfall I ran into: Ensure the implementation of OnOverlap has the following parameters:
class AActor* OtherActor,
class UPrimitiveComponent* OtherComp,
int32 OtherBodyIndex,
bool FromSweep,
const FHitResult& SweepResult
I tried following an example on an extremely similar piece of code and the documentation did not include the latter two parameters.