Windows 10: Pressing arrow keys causes mouse pointer to snap to the top left of corner of my screen

I have this really weird and frustrating issue where when every I press any of my arrow keys, the mouse pointer instantly snaps to the top left of my screen. I have no idea what is causing this. Does anyone know how to fix this?

:)

 

Mouse pointer moving on arrow keys pressed

I'm encountering a strange problem on my W10 computer, for a few days my arrow keys have been "driving" my mouse pointer. Pressing the left arrow key will move the pointer a few pixels left, etc.

The first thing that came to my mind was "oh well, I must have enabled Mouse Keys inadvertently". But Mouse Keys use the numpad and even then, it's not enabled. Rebooting doesn't help, but I've noticed it doesn't happen if the current window is ran as another user (Administrator) or if it's the Task Manager, which suggests the event filter that's catching the key press events is only active on my UID.

I've tried killing various processes but I'm running out of ideas. I'm fairly sure it's a dumb issue but it's been driving me nuts.

 

Mouse pointer automatically moves to the top left corner of the screen

My mouse pointer automatically moves to the top left corner of the screen. Restarting the computer does not help. Even when the mouse is unplugged the pointer still moves. It moves to the left slowly but up quickly, almost instantly. I am on a desktop
PC with no touchscreen running windows 10.

 

Windows 10 - Mouse pointer moves automatically to left/right top corner

Mouse pointer is moving automatically to left side top corner. Please advise if some settings have to be changed to stop this behavior of mouse pointer.