Game-breaking input stutter when using keyboard and mouse

Game-breaking input stutter when using keyboard and mouse together on PC. On PC Windows 11/10 there is a fully reproducible micro stutter that occurs every time a keyboard key is pressed or released while the mouse is moving. The stutter lasts a few milliseconds but is clearly perceptible and disrupts camera movement aiming consistency and overall gameplay making the game effectively unplayable with keyboard and mouse. The issue occurs at high and stable framerates with no visible FPS drops and only when using keyboard and mouse together. When using a controller the issue does not occur. Steps to reproduce are simple move the mouse left and right continuously and while moving the mouse press or release any keyboard key such as W A S or D and a short but distinct stutter occurs exactly at the key press or key release. Expected behavior is smooth uninterrupted camera movement with keyboard and mouse. Actual behavior is a short stutter on every key press or key release during mouse movement. The issue is one hundred percent reproducible. Troubleshooting already performed without success includes clean GPU driver reinstall testing multiple driver versions full game reinstall different keyboards and mice different polling rates all overlays disabled background software disabled and fully updated Windows. The issue appears related to the keyboard and mouse input pipeline other PC players report identical behavior and controller input does not show this issue suggesting an input or camera synchronization bug introduced in a recent update.