i have never had this issue before and as far as i can tell it only happens on ARMA3. whether i am on the main menu or in game (single or multiplayer) the game runs smooth as normal until i press any key or click with my mouse, when i do the game freezes for a couple of seconds and then returns to normal. if i hold down a key the game freezes for a much longer duration, the program never closes just freezes for long periods of time. because of this the game is simply unplayable every time i try to move i hold "W" and it freezes. when i play i can freely spin the camera with no issues.

this has happened since the June 9th update, nothing else on the PC has changed since that point.

*EDIT*
i have now found that BattlEye is the issue and disabling it seems to stop this and fix it. BUT and this is a big BUT, i cant play multiplayer with it disabled. i will try to find a fix and continue to edit for others that may experience this issue.