I have the same problem in my Acer Iconia W4 820 after upgrading to Windows 10 from Windows 8.1. Certainly I feel that there is some incompatibility with this H/W as it worked well with Windows 8.1.
Microsoft, I am downgrading back to Win 8.1. Please keep the forum updated when you find the fix. BTW, there are few things great in Win 10 but it freezes a lot and still not a stable build. The keyboard opens up on top of the text you are typing, and you cannot see what you are typing!