I have applied similar solutions and I have had the same results —–> it works but it is not calibrated.
The problem is the jumper company, its website is not updated (2014) and does not respond to email. to see if you’re lucky and they respond.
Do you know if you can see the touch panel version without having to open the tablet?
Where did you get the official drivers? because in the jumper web there is not. I have got drivers from a Chinese website, from this forum, from a russian forum and from my vendor and there are only two versions of the touch screen driver (03-27-2017 and 05-27-2017).