How can i link a static string variable to another scene and display it?

Hi all, I am just starting to learn how to use Unity to create a simple 2D game, and i have encountered a issue. I try to search through forums and also follow the Unity tutorial https://unity3d.com/learn/tutorials/projects/roll-ball-tutorial/displaying-score-and-text step by step but to no avail.

My issue is that , in one scene i use input field to let user key in name (string) and save them, using the script below:

 public class SetPlayerName : MonoBehaviour
 {
     public InputField usernameInput;
     public static string playername;
    
     void Start()
     {  
         if (playername != null)
             usernameInput.text = playername;      
     }
 
     public void SaveUsername(string newName)
     {
         playername = newName;
         SceneManager.LoadScene("ChooseCharacterScene");
     }
 
     // Update is called once per frame
     void Update () {
         
     }
 }

So that the name is saved into a static variable called playername.

Now in my next scene, I want to display the name. What I did is create a UI text in canvas. Create a game object that store the following script:

 public class DisplayName : MonoBehaviour {
 
     public Text p1name;
     
     // Use this for initialization
     void Start () {
         p1name.text = SetPlayerName.playername;
     }
     
     // Update is called once per frame
     void Update () {
         
     }
 }

and just pull the UI text element icon put into the script just like this: PlayerName is my ui text element name

What happens is that when playing the scene it does not display anything. However if i change my p1name.text = "Hello", it does display the correct string.

Is it because the way i import the static variable is incorrect thus it is not displaying on canvas?

Please forgive me if i asking a noob or amateur question. Welcome all the replies and help!