They are swinging but they have no pace at all. A half fit Shaheen was bowling faster than them.
The swing also happens because they bowl medium and the ball is new, so without any pace the ball would react more. They do trouble the batsman early on, but issue is, after the first 3 overs, the bowlers become dead. It becomes very easy to score runs against them.
Babar and Rizwan batted terrible. Shan on the other hand played out the ball and after the 3-4 overs, the ball was just acting normal and Shan easily scored with Iftikhar.
There bowlers fail to do anything on the same pitch, because once the ball is not new anymore, they dont have pace to save themselves.
Thus, the swing is for 2-3 overs, lethal against openers, but if one survives it, you can easily tonk the same bowlers for runs.
Had Faheem Ashraf been born in India, he would had been the Waseem Akram for them