Disabling button from another class

I know this question has been asked before or similar questions asked but none of the solutions has yet fixed my problem.

I have a winform that has a button named hitButton. All I need to do is to disable this button from another class (i.e. not the form class).

My form class is:

public partial class BlackJackTable : Form
 {
 }
 

My separate class is:

class GameWon
 {
 }
 

I have tried exposing a public method in BlackJackTable like this:

public void DisableButtons()
 {
     hitButton.Enabled = false;
 }
 

and accessing from GameWon constructor (it doesn't seem to matter where in the class I access it from though) like this:

public BlackJackTable blackJackTable = new BlackJackTable();
 
 public GameWon()
 {
     blackJackTable.DisableButtons();
 }
 

I have tried using a variable in GameWon:

public Button hit;
 

and assigning from blackJackTable:

GameWon gameWon = new GameWon();
 
 public void Assign()
 {
     gameWon.hit = this.hitButton; // or just = hitButton;
 }
 

and disabling from GameWon:

hit.Enabled = false;
 

I have tried a couple of other things but none of them work. I'm guessing I'm missing something obvious as none of the methods I've tried have worked.

Any thoughts appreciated!

Update

I have managed to do the latter method with textboxes and pictureboxes, what's the difference with a button?

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