Thanks for this question.
Yeah, let's break this down :D
Let me say it categorically, India Pakistan match in the last 20 years have been wrongly projected by former cricketers specially from Pakistani side
A long time ago India used to feel the pressure of playing against Pakistan
Last 20 years have changed it all
Still Pakistani former cricketers unable to accept that reality or probably not aware of this and a Minority portion of Indian former cricketers also feel this way but just minority not majority
See it's not nerve that decided the game, it's stats
Pakistani former cricketers are living in the past which they are completely oblivious to the reality that India is far stronger side than Pakistan and would beat them 99% of time
What happened in champions trophy was just a fluke, Fakhar Zaman was unknown batsman therefore Indian team didn't know where to bowl to him(Pakistan is so dependent on this unpredictable factor which is missing currently as everyone knows what Pakistan is going to offer now, all of their cricketers are known by Indian cricketers so there is no unpredictability anymore)
He isn't an unknown batsman anymore and Indian bowlers know exactly where to bowl to him
It was quite evident in recent Asia Cup.
Plus Bumrah was a new kid on the block in international cricket and had a new ball problem, he did that against West Indies as well in 2016 T20Is match in WC
He no longer have this problem
Fakhar Zaman changed that match due to that no bowl otherwise Pakistan would have lost again badly to India in champions trophy final
So the point is Pakistan have been highly overrated by the so called experts in recent times.
LIGHTING DOESN'T STRIKE IN THE SAME PLACE TWICE SPECIALLY SINCE PAKISTAN'S WIN IS SO DEPENDENT ON LIGHTNING STRIKE :D