Threads don't work the same for pc and android?

I implemented a thread for my unity project and it works fine on pc but it is broken for the android. The thread is running a recursion and for some reason teh values returned are messed up. Can;t really explain what happens there yet though

What I do is create the thread on another script and run the method...is this the way to go for android apps?

this is my thread:

   public int GetPCNextTurn(int[][] board,int height,int width,int sequence)
         {
             
                 this.height = height;
                 this.width = width;
                 this.sequence = sequence;
              
             
             this.board = board;
            
             weights= GetWeights(sequence);
 
              CompPlayTurn(board,weights);
 
  Thread myThread = new Thread(() => CompPlayTurn(board, weights));
      myThread.Start();
 
 return col2play;
         }

The pc used to mess the board I sent it (the code ruins the board with teh recursion but for some reason the change becomes permanent when using threads ) so I send a copy of the board.

But the android not only messes the board still, but the value returned is always the same...

Basically I have a recursion AI that should return the move to take, and this is what I ;d like to put in a thread..

Any suggestions?