Waris Shah's Heer has been translated into English several times, into Urdu, into Hindi, and into a number of European languages, and no translation has satisfied anyone who reads the original.
The difficulty is not the story. It is that the poem is written in a fixed metre with an internal rhythm that carries the recitation, and it is dense with the vocabulary of eighteenth-century Punjabi trades, castes, medicine, law and abuse, most of which has no equivalent anywhere.
The recitation tradition is a separate art from the text: a Heer singer holds a village for hours on a tune, and the poem was made to be performed rather than read.
Selections are widely available in English. Complete versions exist and are hard to find.
The same applies to Bulleh Shah, whose kafis are translated constantly and whose Punjabi wordplay does not survive.
Punjab's greatest literature is effectively inaccessible in any language other than Punjabi, in either script, and that is the practical reason it is not part of world literature in the way comparable Persian and Bengali work is.
The nineteenth century English versions were made by administrators and missionaries for whom the poem was ethnography. The twentieth century ones were made by Punjabis for readers who had lost the language. Neither audience is the one it was written for.
The problem is the form. It is written in a metre made for singing, in a Punjabi thick with local reference, and what survives translation is the plot, which is the least of it.
The performance tradition is the real transmission. A Heer sung by a Punjabi singer to a Punjabi audience does not need translating and does not travel.
Literature on the Heer recitation tradition.