I am having a similar problem- I upgraded my Venue 8 Pro to Windows 10 (went OK after I made enough space available on c: drive) and for several months the Dell Active Stylus worked as well as it did before the Windows upgrade. Last week, the pen ceased to be able to "click"- that is, the pen won't write or open buttons or close windows or crag scroll bars etc. It still functions in the sense that you can see the little dot when the pen is close to the screen, but you can't do anything with it. I have posted this elsewhere but haven't gotten any information I can act on. Thanks for your post- I will look for that. BTW I have updated the drivers I found on the Dell Support area for the Venue 8, but this didn't solve the problem.

My original pen misbehaved too! Except in my case it simply stopped working and despite a new battery I had to keep removing and replacing the battery for it to work! A new pen has arrived today (thank you Mr Dell) so we will see how it goes but it doesn't solve the input problem :-(