AFAIK, nobody proved that Pi digits sequence is normal. See https://www.quora.com/How-random-are-the-digits-in-pi https://www.quora.com/How-random-are-the-digit

AFAIK, nobody proved that Pi digits sequence is normal. See https://www.quora.com/How-random-are-the-digits-in-pi https://www.quora.com/How-random-are-the-digits-in-pi . So it quite possible for some finite sequences to be omitted from the Pi digits sequence.