Help with second monitor problems

I have been using two monitors for quite some time now, but this new problem has been very annoying to me. Lately, whenever I would try to drag a window or click and drag anything in the second monitor(not the main screen monitor) it would reset the click and drag and start one after I move a good 3 inches on the screen. So for example, I would try to move a window to the second screen, as I am dragging the window from the first screen to the second, the click and drag stops right as the mouse touches the edge of the monitor. It doesn't snap to fill half the screen or anything, it just stops. Another example is when I try to click, drag, and highlight desktop icons in the second screen, it just seems like I'm clicking and dragging many times over and over again. Also, when I am on a website trying to highlight a great amount of text, it does the same thing except when you highlight a piece of text, and when you try to click and drag again, it's basically like copy and pasting. It's very annoying. If anyone has any idea of what is happening, please help!

Unless you know how to pry open the mouse (without destroying it) and give it a good cleaning, replace it. My Microsoft mouse was misbehaving. I thought I had malware. With the mouse replaced, back to normal.

For the monitors, have you verified the #1 and #2 are oriented correctly?