Stylus pen for Ubook Pro N4100

Please help!

My stylus pen suddenly stops working on my pc-tab. I charged it in full and tried it on my phone and it works. I don’t know what kind of pen is this but i got it as a bundle package and it was fine until yesterday it suddenly stops working. It has silver color with orange top. I can’t find the pen through bluetooth.mIs there any driver or anything I need to install? Why it suddenly not working? The screen still responding to fingertips but not to the stylus pen