How old are you exactly?
Let's be clear in our "Pakistani" minds first. This is not a border dispute between Pakistan and Afghanistan. It is something that Pakistan inherited from the British after they meted out a serious hiding/military defeat on the Afghans and their then ruler agreed to sign off and agreed to the appointment of Sir Mortimer Durand to adjudicate the line of division between the British Empire and Afghanistan. India's division was between 3 parties, the British, INC, and ML. There was no Afghanistan in the picture then nor now.
The Afghans, post the creation of Pakistan, think that this adjudication no longer applies. Pakistan thinks differently.
Second, this issue has been discussed with EVERY single ruling disposition in Afghanistan since this is a central Afghan talk track on discussions with Pakistan. Every Afghan who rules the roost has to prove his "Afghaniat" by bringing up the Durand line with Pakistan to show to the rest of his Afghan compatriots that he means business.
Pakistan has always ignored it till they started murdering Pakistanis in large numbers. If things were kept to a "dispute" in talks, no problem.