Secondary Monitor Touchscreen issue after Window 10 Anniversary update

I have the following. UD3900, Surface Pro, Dell S2240T
After Windows 10 Anniversary Update
everything work well. except touch screen on my Dell Monitor.
If i setup my Surface as Primary screen and Dell S2240T as secondary screen in extended display mode.
The touchscreen is functioned but all it touch point it based on Primary screen area ( like duplicate screen function )
If i set Dell S2240T as Primary and Surface Pro as Secondary , Both touchscreen work perfectly.
Any recommended solution to rectify this issue since I prefer to use Surface as Primary and Dell S2240T as secondary.

Been try delete and clean and fresh reinstall the driver and still have same problem

Can close the topic.
Found the issue
I have a DVI to VGA adapter plugged at the UD3900 port
only adapter plugged in and not connected to anything
removed the adapter everything work fine.

Hi Ng,

Thanks for posting and glad to hear that you were able to get your touchscreen to work properly with our dock again!

Thank you,

David W.
Plugable Technologies