tkinter button color won't change (non-click event)

I created a program to move a knight around a chess board touching every square without touching the same one twice, starting from a random location. I am attempting to show this action using tkinter by changing the color of the square (which is a button) to red as the knight moves.

The Chess Board is made of tkinter buttons and they relate to the "Square" class. The program sets the correct colors when creating the grid, but won't change them during execution.

Here is the reduced code (as instructed to provide).

    from tkinter import *
    from tkmacosx import Button
    import random
    import sys

    WIDTH = 800
    HEIGHT = 1000
    GRID_SIZE = 8


    class Square:
        board = []
        def __init__(self, x, y, touched=False):
            self.touched = touched
            self.board_btn_object = None
            self.x = x
            self.y = y
        
    
        def create_btn_object(self, location):
            btn = Button (
                location,
                width=100,
                height=100,
                text= f"{self.x}, {self.y}", 
                bg=None
            )
            self.board_btn_object = btn

            Square.board.append(self)
    
        @property
        def is_touched(self):
            self.touched = True
            self.board_btn_object.configure(bg="red")
    
        @staticmethod
        def randomlocation():
            return random.choice(Square.board)


        def __repr__(self):
            return f"Square({self.x}, {self.y}) touched={self.touched}"


    class Knight:
        def __init__(self, x, y):
            self.x = x
            self.y = y


    def main():
        root = Tk()
        root.configure(bg='blue')
        root.geometry(f'{WIDTH}x{HEIGHT}')
        root.title("chess chaser")
        root.resizable(False, False)

        top_frame = Frame(
            root,
            bg = "red",
            width = WIDTH,
            height = height_prct(10)
        )
        top_frame.place(x=0, y=0)

        bottom_frame = Frame(
            root,
            bg="black",
            width = WIDTH,
            height = height_prct(10)
        )
        bottom_frame.place(x=0, y=height_prct(90))

        center_frame = Frame(
            root,
            bg = "green",
            width = WIDTH,
            height = height_prct(80)
        )
        center_frame.place(
            x=0,
            y=height_prct(10)
        )

        make_board(center_frame)
        top_menu(top_frame)
    
        root.mainloop()


    def height_prct(percentage):
         return (HEIGHT / 100) * percentage


    def width_prct(percentage):
        return (WIDTH / 100) * percentage

    def top_menu(top_frame):

        run = Button (
            top_frame,
            width = 100,
            height = 50,
            text=f"Run",
            command = play_game
        )
        run.place(x=30, y=10)


    def make_board(center_frame):
        for x in range(GRID_SIZE):
            for y in range(GRID_SIZE):
                b = Square(x, y)
                b.create_btn_object(center_frame)
                b.board_btn_object.grid(
                    column=x, row=y
                )
                if (x+y) %2 ==0:
                    b.board_btn_object.configure(bg="grey50")
        return


    def play_game():
        knight = place_knight()
        sys.exit("Done")


    def place_knight():
        coords = Square.randomlocation()
        coords.is_touched
        x = coords.x
        y = coords.y
        knight = Knight(x, y)
        return knight


    if __name__ == "__main__":
        main()

I have tried using self.board_btn_object.change(bg="red") and .update and .after.... nothing works to change the color.

If I change code and bind left click to change the button to red, it works fine; however, I want it to change when the KNIGHT is positioned there.

source https://stackoverflow.com/questions/74602264/tkinter-button-color-wont-change-non-click-event