Mouse clicking became too sensitive after Sierra upgrade?

[hajime]

Hello, after upgrading my MBP 2010 17" to Sierra, I noticed that even I did not click the trackpad nor my logitech mouse, often things got selected just as I moved the cursor across the screen. Sometimes I wanted to drag a window across the screen. However, even by clicking and dragging, the operation became increasing the size of the window.

Is there a way to fix these problems?

 

[hajime]

It now looks like after upgrading to Sierra, even by just moving the cursor across the screen without clicking the trackpad, the left click action is automatically and randomly performed. Anybody knows how to fix this issue?