Hi Bia Martins, I'm sorry for the late reply. May you please clarify what you mean by the screen is "stuffed"?
With regard to your pen problem, does your tablet driver show as "Device connected"? What driver version have you installed?
Kindly try the following steps so we will know the root cause of your issue:
If your issue is not resolved even after following the above-mentioned steps, please take a video as you follow the steps above and in testing your tablet with your drawing programs. After which, please send the following information to email@example.com so we can assist you further, including the answer to my questions above:
HUION Customer Support