But Pakistan's main problem is that none of their players are performing consistently. Saim Ayub, Shan Massod, Babar, Rizwan, Shafique, Agha Salman each batsmen in Pakistan squad against Bangladesh were talented and experienced. Also Shaheen Shah Afrida, Khurram Shahjad and Naseem are good bowlers each. However, Pakistan lost both the matches. Pakistani players need to be more diligent. Otherwise the team will not be able to perform well.
This is an important reason. It is true that Pakistan team considers Bangladesh as weak. Even if the opponent is weak, Pakistan should not consider the opponent weak. Pakistan declared their innings with 448/6 in the first innings. Pakistan could have easily collected another 100+ runs. But they thought the Bangladeshi batsmen would not do well. And even after collecting 448 runs, Pakistan can take a decent lead. But unexpectedly, Bangladesh collected 565 runs in the first innings. And in the second innings, Pakistan batted very badly against the Bangladeshi spinners, and gave a target of only 30 runs. As a result, Bangladesh won very easily.
The second match was more competitive. But I would say Bangladeshi players were very confident. And they were able to defeat Pakistan by staying confident.