Random deselect

So about 30-40% of the time whenever I’m in the drum editor window and there’s an event selected, I will press and hold ‘Ctrl’, with the intention of moving it to the left or right with the ‘Num +’ and ‘Num -’ keys, and after about half a second or so the event with become deselected, and I’ll have to reselect it to use any of the hotkeys on it. This also occurs sometimes when an event is selected and I will move it down or up with the arrow keys and after moving it only one row either it will become deselected, and I will have to select it again to move it. This also happens when I press and hold the Shift key while an event is selected. This is rather frustrating whenever I’m “in the zone” so to speak because I’m very fluent with the key commands and having to stop and reselect events with the mouse takes more time than I’d like. Has anyone had a similar issue?