Strange LeanTween issue

I'm working on an animated menu that uses LeanTween. I have a large amount of input buttons set up to navigate the menu. When the "Submit" button is pressed, I tween the camera to the next stage of the menu. The Submit button is activated by return, space, and joystick button 0 on all joysticks. Everything works fine using space and joystick button 0. However, when it's activated using return, the tween doesn't occur. I've tested it using breakpoints and LeanTween is being called, but nothing happens. Here's some sample code:
state = StateType.SelectingMode;
LeanTween.move(Camera.main.gameObject, modeSelectCamera, 0.5f); LeanTween.value(gameObject, UpdateZoom, Camera.main.orthographicSize, modeSelectZoom, 0.5f);
modeSelectText.SetActive(true);
Does anyone know what could be happening here? I'm stumped.