The issue with Jackfruit cultivars is that there is an infinite variety of them. Unlike mangoes and many other fruits where less than 1% of seedlings are going to produce a decent fruit, many jackfruit seedlings are actually pretty good and produce in just a few years. Anyone who grows out a seedling and likes something about it can call it whatever they want and graft out all they can. So maybe "Crunchy" is just a selected seedling that they are propagating, or it may be that they just planted the seeds of a crunchy fleshed fruit and assumed the seedlings would be similar. I would definitely check for a graft.