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. Everyt$$anonymous$$ng 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 not$$anonymous$$ng happens. Here's some sample code:
state = StateType.SelectingMode;
LeanTween.move(Camera.main.gameObject, modeSelectCamera, 0.5f); LeanTween.value(gameObject, UpdateZoom, Camera.main.orthograp$$anonymous$$cSize, modeSelectZoom, 0.5f);
modeSelectText.SetActive(true);
Does anyone know what could be happening here? I'm stumped.