This is not something new, Pakistan team is always having a whitewash at Australia. They are not able to manage pressure when playing at Australia. See they have good advantage in first innings but were not able to capitalise that advantage in second innings. Babar Azam who is backbone of Pakistan batting was not able to score even a fifty in his six innings, his highest score was 41. Players like Babar Azam need some break they are over hyped.
In the third Test match, Pakistan batted well in the first innings but could not win the match due to poor batting in the second innings.Basically, one of the reasons why Pakistan lost the match with Australia was their batting failure. But their mental strength is also lacking, they have been nervous in every match against Australia. Babar Azam is the best batsman of Pakistan team but he is performing very poorly at present. Looking at his batting, it seems that he has never batted well.