Namespace was correct. Discovered the problem though - different function arguments with engine version.
(AActor* Other, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
(UPrimitiveComponent* OverlappedComp, AActor* Other, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)