Numeric keypad is set to scroll

Hey,

I recently started using WebStorm and so far I love it, but there's one issue that is driving me crazy.
The numeric keypad which I usually use to move the caret (with the arrows) is stuck on the scrolling the ddocument, that is the up arrow (with '8') scrolls up, bottom arrow ('2') scrolls down, and left ('4') and right ('6) do nothing.

I'm working on a linux machine in which the behaviour of the keypad is set to work like in windows (move the caret), in it's working well in all other applications that I use, but for some reason in WebStorm the behaviour is weird.
I checked on a windows machine and it behaves as expected.

Any ideas how I can change that setting?
I looked through the settings (Keymap) but couldn't find something for that.

Thanks.