Huion tablet issue - vertical lines won't draw. only horizontals

i have a huion kamvas gt 191 and somehow when tracing vertically, the line won’t draw. only can draw lines horizontally. almost in diagonal but when you start the drawing horizontally, you can go up and down. this issue it’s very frustrating that I can’t use the benefits of a display tablet. if needed, I can execute a video capture with the issue. regards