Boolean Toggle Cross-Script No Worky?

I have a GameManager script holding the bool variable bDisplayMenu. I want to toggle this boolean to control the menu display in the PlayerMovement script. It toggles on, drawing the menu when I press the assigned button, but never disappears. I would appreciate the help figuring this one out.

This is the relevant bit of GameManager:

 public class GameManager : MonoBehaviour 
 {
     public static bool bDisplayMenu;
 
     void OnGUI()
     {
         if(bDisplayMenu == true)
         {
             Texture2D tSkin = Resources.Load("Polkdot") as Texture2D;
                 
             GUI.Box(new Rect(20, 20, 100, 380), "Blah");
                 
             // DRAWING SLOTS - NOT INTERACTABLE ========
             GUI.Box(new Rect(40, 40, 60, 60), tSkin);
             GUI.Box(new Rect(40, 120, 60, 60), tSkin);
             GUI.Box(new Rect(40, 200, 60, 60), tSkin);
             GUI.Box(new Rect(40, 280, 60, 60), tSkin);
         }
 
         else
         {
             Debug.Log ("Else");
         }
     }
 }

And PlayerMovement:

 public class PlayerMovement : MonoBehaviour 
 {
     void Update()
     {
     if(Input.GetButtonDown("Menu"))
     {
         Debug.Log (GameManager.bDisplayMenu);
         GameManager.bDisplayMenu = !bDisplayMenu;
         Debug.Log (GameManager.bDisplayMenu);
     }
 
 }

If it helps to note: I tried copy-pasting the OnGui text from GameManager to PlayerMovement (adjusting the variable reference) and when I do that it simply never fires.

Any help is appreciated, thanks!