When I enable Reg Sequence, or switch to a new Registration Bank that has a sequence, I always have to press once to 'prime' the sequence and put it on to 1. Just checked on S970 and Genos.
Maybe I've misunderstood the original post. With the sequence indicator already on 1, are you saying that it still requires an extra press to get to 2? That would be unusual, and I've not encountered it.