How to declare networked functions in 4.22?

your .h is fine, but in c++ you need to have it like that :

bool AHOPCharacter::SetMovementInputEventServer_Validate(FVector NE_MovementInput) { return true; }

 void AHOPCharacter::SetMovementInputEventServer_Implementation(FVector NE_MovementInput)
 {
     MovementInput = NE_MovementInput;
 }

the validate function is where you should do the check for anti cheat like behaviours

Wiki is still up to date, the only change is that “WithValidate” is now mandatory for server functions :