I don’t know what this is or what causes it but sometimes my mouse pointer would turn into a square, scroll bar. It will keep flashing and I have no idea what it is or what caused it. If I navigate to a page and attempt to use the scroll wheel on the mouse to scroll down, the page will scroll down, but then scroll right back up to the beginning. It is like the the scroll wheel is stuck, but physically, it is not.
I just played around with the scroll button (middle key above the touchpad) on my laptop’s keyboard and it fixed it.